Yep. This is the same strategy Instagram used a few years ago in copying Snapchat's Stories format, and likely has the same goal. The idea is not that Instagram can take back TikTok's audience — those users are well and truly lost — but rather that it can deny existing Insta users any reason to even try TikTok in the first place. (Because they can get the same form factor without downloading a new app.)

From what I've heard, the Stories copying strategy did successfully contain (but did not roll back) the Snapchat threat to Insta. So there's some reason to believe they can hold the line against TikTok with this approach too, even absent the possibility of a government ban.

I expect this sort of convergence will continue in the future. Whatever one might think of fast-following as a strategy, scale plus rapid copying of features does seem to work.