This is notable because many of the advanced features in Garmin watches - and watches from other companies - are made by Firstbeat. Stuff like training load, all day stress, VO2max, training effect, sleep quality, etc.
Garmin says they will continue licensing these features to their competitors. (You have to wonder how long that will last.) They still stop paying licensing fees however, which have limited which features they put in which devices.
TL;DR probably more features coming to Garmin watches and less to other watches in the long term.https://www.dcrainmaker.com/2020/06/garmin-acquires-firstbeat-analytics-a-quick-analysis-of-the-winners-and-losers.html