Building satisfactory alternatives to Office, Workspaces etc. isn't a monumental task by any stretch. With the sudden demand that you predict, they'll spring up like weeds.
This might be ham-fisted and crude, but in the end I see a lot of positives.
Developing the product itself isn't the reason.
Also, the competing EU-based service might be strong competitors to the ones in the U.S., among people like me who are privacy conscious. I don't use Google services, but I'd be happy to consider using GDPR-compliant services based in Europe.
Libre office is a third option, but does it have much usage? Why or why not?
Could you sustain a development team capable of creating this with a limited market and revenue stream?
This is how promising companies are swallowed by the market leaders.
Market wouldn't be limited and potential revenue streams would be huge. So yeah. Just as a reminder, this is still assuming that there is a significant window where the big options aren't available for Europeans.