Here’s a good writeup on the new M1 13” MacBook systems [https://www.ifixit.com/News/46884/m1-macbook-teardowns-something-old-something-new|M1 MacBook Teardowns: Something Old, Something New]
As we can see comparing the older Intel and the new Apple M1 models we can see the battery appears to be the same and like the older one also glued in!
Early 2020 13" Macbook Air
[image|2299178]
M1 13" Macbook Air
[image|2299177]
So I would say its very possible to replace it!