I have blocked some on Playtomic for similar reasons, and I can still see when they have joined a match. When I click on their profile, it shows that I have blocked them so I do not join these matches with them.
I guess the experience is similar from their side. They still see the open matches I join, and can see that some players have blocked them (I used to see "Anonymous" for those that blocked me and was not able to see their profile), and can still join them if they like confrontation by someone who blocked them.