Focusing on native mobile apps over web for launch is a completely sound strategy. 80% of Twitter use is from mobile, and probably near 100% for Instagram since they barely have a web version. But I’d expect them to do a web version relatively quickly to appeal to Twitter refugees.
But that's really odd because most mobile MVPs are either just PWAs or some React Native shit compiled to binaries.
Why the hell wouldn't they just release it on the web?