Last time my MBP (mid-2015 15'') was in the shop, I just "purchased" the latest model, only to return it when my old machine was sent back. The 14 days no questions asked return policy makes it possible even if the turnaround time is 7+ days. I did communicate my intent very clearly prior to the "purchase" (really just a loner), and multiple Apple Store employees I talked to were very supportive.
Incidentally I got to live with the new butterfly keyboard for a week or so. I've been hearing horror stories about it for years at that point, but turns out it was okay. Not gonna win any awards, but after a few hours I got used to it like any other keyboard, had no problem touch typing, and didn't notice any increased rate of errors. The arrow keys did take some getting used to, though, and the lack of physical Esc and function keys was a nuisance in a small number of scenarios.
Incidentally I got to live with the new butterfly keyboard for a week or so. I've been hearing horror stories about it for years at that point, but turns out it was okay. Not gonna win any awards, but after a few hours I got used to it like any other keyboard, had no problem touch typing, and didn't notice any increased rate of errors. The arrow keys did take some getting used to, though, and the lack of physical Esc and function keys was a nuisance in a small number of scenarios.