It'll be interes
Its a bit late to be changing your order… at this point, you’re more likely to get delayed, unless there one already in inventory.
It'll be interesting to see if or how "late order changes" affect EDDs.
Tesla has a finite number of "build slots" which already filled up for the quarter a few weeks ago.
Using my order as an example, I recently changed from 19" to 20" and added a tow hitch just days ahead of my earliest EDD.
I see a number of possibilities:
1. Tesla could build my original configuration, but instead of it going to me, it'll go to the next person in line (or inventory). In this case, my new configuration would have to go to an April-June build slot.
2. Tesla could build my new configuration on the same day that my original configuration was scheduled to be built, but with different wheels and a tow hitch. In this case, the change might not affect my delivery date at all.
3. Tesla could cancel my build and move all orders one vehicle closer. This would have the same effect as 1.
4. Similar to 1, someone else who already ordered a Model Y in my new configuration could edit their order (for example, a person who ordered a white, 20", tow may change to a MYP) and Tesla could reassign their build to me and I would inherit their EDD (which could be later, the same, or even earlier than the EDD of my original configuration). In this case, the other buyer who edited their order may then have to wait for an April-June build slot.
Keep in mind I never had a VIN, so the vehicle hasn't been built yet.
Regardless, I'm not the only person to edit an order - I'm sure there are many others making this a moving target for Tesla as well.
It's no surprise that some buyers are hit with huge delays while some seem to skip ahead of others!