It all depends on your perspective. Tesla updates frequently, such that no matter when you buy your vehicle, it's a certainty that your vehicle will become 'obsolete' (in quotes because of course it won't be obsolete--just not the cutting edge) shortly after you buy it. There are no Tesla vehicles that remain stagnant for years, nor are there to likely be any in the foreseeable future. So trying to time your purchase so as to get one more hardware change when there will be several over the vehicle's lifetime is a losing proposition.
The resale 'hit' follows a similar path--your car is going to 'lose' value several times over its lifetime due to the new cars getting better. Whether you buy 60 days before a hardware change or 60 days after, this remains the case. Further, any resale 'hit' is only realized if you were looking to sell your vehicle at the time, similar to stock market gains and losses. Over time, each resale value hit will diminish as the vehicle gets older, until you reach a point where it's largely inconsequential (eg your car is going to sell for $15k or $18k, not a huge diff relative to the purchase price and time spent trying to time your purchase exactly). Unless you are buying the car intending to hold it for only a year or two, I believe you're overthinking it.
And of course in the end, the only hit you are taking for certain is extending the period during which you do not own a Tesla. Each day that passes in that category is an 'actual' loss, and one that you can never regain.