[mottomotto]

I think it's only a red flag if you don't want to work remotely. I've been doing it for about 1.5 years straight now with a 6 month stint in the past a couple years ago. With a wife and young kids, it's great. I can have lunch with them. I don't have to deal with as much office politics. My employer keeps us fairly well informed about the health of the startup.

Are there pain points? Yes, communication can be difficult and the transition can be difficult for managers. People seem to really vary in their ability to comprehend how async communication can work (as in, what needs to be a group announcement on a call versus just an update in Slack or email).

So I personally wouldn't see the change as a red flag. Having had my current experience, I would be delighted and would be considering where to move to maximize taking advantage of being remote. But it really is a "your experience may vary" based on what you're looking for.