What are they hoping to get out of it? Wouldn't this just inconvenience their own users?
Like IBM with Redhat, they tried to overstep their position and exert undue control, so the community rejected their status as BDFL. Now IBM has Rocky and Liberty to deal with, and Redis has Valkey rapidly gaining credibility as the go-to solution. The social contract of FOSS goes both ways, and greed is righteously punished with the loss of power.
Also, there's the thing where these other projects have been using the name since forever, so there's already a history of non-enforcement.
That is part of it....these projects are older than the trademark, by quite a bit.
[0]: https://trademarks.justia.com/878/05/redis-87805452.html