Tesla is building a new "Grohmann machine" battery pack assembly line at the Nevada Gigafactory
the size of a football field. This new, large assembly line is assumed to be making the lighter, cheaper, faster to assemble Standard Range battery pack.
So Standard Range is not going be replaced by Medium Range, unless you think Tesla is throwing away all that capex.
I believe there are more benign explanations as well for the website changes:
But it's not out of question that Standard Range will be announced soon, when Elon originally announced the Medium Range battery pack he mentioned February 2019 as the introduction date:
Elon Musk on Twitter
"It’s a long range battery with fewer cells. Non-cell portion of the pack is disproportionately high,
but we can get it done now instead of ~February"
And it's "~February" now.
OTOH as recently as January 30 Elon updated their "~February" timeline to "middle of 2019":
Emmanuel Rosner:
"First, I wanted to ask you about the short-range Model 3. What are your latest thoughts in terms of timing of introduction? I think at some point, you had in mind to do it in the - maybe the first half of this year. And just to clarify, when you're sort of talking about the outlook for 2019, the number of deliveries up 50% and then the margin target for Model 3 to get to 25%, does that assume that you're introducing a lower range, the short-range Model 3 at some point during the year?"
Elon Musk:
"Well, you could call it the standard range, but it's maybe short by Tesla's standards, but it's long range by other manufacturers' standards. So - but yes, we expect to introduce the standard range Model 3 sometime - probably the middle of this year is a rough, rough guess. And we're working hard to improve our costs of production, our overhead costs, our fixed costs, just costs in general. I think this past year, while extremely difficult, has driven us to a high level of financial discipline. I think we're way smarter about how we spend money, and we're getting better with each passing week. Yes."
Maybe those plans have changed again.
Some other possibilities:
- They might be introducing the new battery pack at a lower price point due to the lower assembly and cell costs, but with the same "Medium Range" rating.
- They could improve SR margins via bundling: for example unbundle Premium Interior but add AWD initially. This would allow a rough introductory price of $39,000, with the $35,000 version introduced later in the summer.