Volvo and Saab have been a market failure and had to be bought out by the Chinese. Audi is really the only one doing fine in the premium segment with primarily FWD cars (although they are mainly famous for their AWD quattro system).
The packaging advantage of FWD is largely related to the elimination of the drive shaft. This results in a hump which the middle rear passenger has to straddle and significant efficiency loss as well as extra cost. There is also a traction advantage related to the engine being over the drive wheels. These factors are non-existence in an EV.
The packaging advantages of FWD are two-fold, first and foremost it allows for transverse engine placement (sideways). This is the main reason why Mercedes did it in the CLA, and why the likes of Skoda Superb are so vast in interior space, because less of the car needed for basically "the bonnet". Audi uses transverse engine placement only in their small models that share VW platforms, the Audi A1, A3, Q3 and TT.
The other benefit, lack of central tunnel, is actually used very little in larger premium cars for a simple reason: it is used for exhaust and with AWD sister models having two different packagings is found an unnecessary cost anyway. All those longitudinal FWD Audis, where engine takes just as much space of the front as on RWD, have central tunnels still. It is not a consideration for them or their buyers.
Audi uses none of the FWD packaging benefit in larger models.
This brings us to the main FWD benefit in premium, above compact cars that is: FWD has a unique driving dynamic preferred by some demographics. Audi today makes FWD cars because their demographic demands them, just like BMW makes RWD cars for theirs - historical reasons for both of course. Audi has toyed with RWD in labs and it has always been nixed eventually (outside of R8) for fear of alienating customers. One thing, I guess, we are skirting around (no pun intended) is that FWD cars sell a lot to the high-end family car as well as female demographics, where its driving dynamic is preferred. It is no wonder Audi TT, even in its FWD form, sells a lot in the latter demographic. With CLA, Mercedes can target these demographics - and does. It is not targeting the hardcore BMW petrolhead or Porsche enthusiast.
Audi even makes the Audi A8 in front-wheel drive. These cars don't have 50:50 weight distribution, because in those demographics that buy these FWD cars, it really doesn't matter. For them FWD is the safe, sensible choice that they are familiar with. They are not buying a track weapon, quite the contrary.
Tesla being a new manufacturer, of course has no such historical baggage of its own to consider - except for, by now, a core group of fans and early adopters, whom I would assume find RWD acceptable in general and would be suspicious of FWD, if TMC is anything to go by anyway.
But those fans are insignificant in size as a group for Model 3 considerations. What Tesla does have to - and probably does - consider is what kind of historical baggage overall do they need to overcome for market acceptance. They already have an uphill climb for the EV part, no need to go asking for trouble in areas that are not important to them. They will want to sell Model 3 probably to a wide range of people and demographics. In doing so, they will have to select some or few, because not all customer-bases want the same things.
If Tesla wants to introduce their revolution to the masses, it needs to pick its battles carefully and maintain a certain amount of familiarity in areas that are not crucial to change in their revolution. This is why Model S looks like a regular car, it charges around the spot where you'd fuel a car, those Superchargers look like retro gasoline stations and so forth - the magic, for most part is hidden under a layer of familiar. I'm guessing the front vs. rear wheel drive question is not pertinent to Tesla's mission at all, so in theory I would expect them to look at the issue fairly impassionately as a company (individuals may of course have strong views) and choose the one that helps them sell most cars. I don't think EV revolution in itself demands Tesla to take a stance on FWD vs. RWD, it is not important to the question at all.
RWD in Roadster and Model S segments is more common, easy choice - check. In Model 3, there is a lot more FWD competition... so a little more pause. In a hypothetical future sub-compact Tesla, a lot more pause over this question.
So, in my estimation, the question boils down to: What drivetrain configuration helps them sell most Model 3s and thus usher in the EV revolution fastest? I think they will stick with RWD due to their precedent (even though Roadster and Model S are in wholly different categories) and because I think they will target BMW 3 Series, but considering most of the cars sold in the world in general are FWD, the case for an FWD Tesla down the road is not an impossible one. For that FWD driving demographic, taking the leap to EV is already hard for some, why ask them to leap to RWD (if AWD is not economical) too and put in one more roadblock... That was my line of thinking I was getting philosophical on.
p.s. If you are trying to link Volvo's and Saab's failure to their proponency of FWD, I think we can agree to disagree. Hopefully that is not what you are trying to say. Also, I'm betting you there are tons more RWD car manufacturers out there that are no longer in existence.
