If everyone would - in all possible legal contexts - express this disappointment not only here but [a] on social media, maybe even [b] reach out to all important Blizzard contacts or economic services like AfreecaTV , and [c] approach the whole community of people playing Blizzard games to raise awareness for the tragedy this game and its community encounters, then this would at least increase the probability to get some feedback. Otherwise it seems Blizzard will not take serious those few people complaining in this forum that hardly anyone accesses.
Just compare it to the upset on YouTube regarding Diablo Immortal. At least people were able to make some noise.
Unfortunately one cannot expect people to quit playing Overwatch, WoW and all other Blizzard games as a sign of loyalty towards the Diablo and Starcraft 1 community. Even Diablo 3 was still being played by way too many people after the announcement of Diablo Immortal.
Blizzard does not have to care about Broodwar because they have too much success with their other games.
Regarding group matchmaking it is either the case that developers like Grant don’t know how to do it or they don’t care about it (the argument that the remaining developers - if there are any left - do not get enough financial resources from Blizzard is not sufficient, since Grant or any other person could at least keep us informed here).
In a nutshell: no matter how outdated the original code is, a good friend of mine who is a professional game developer explained to me that it is not that hard to realize a decent group matchmaking implementation. Seriously, is there anyone out here who thinks that in 2020 this cannot be done by a few good people within a few months? It is absolutely possible.
From a business point of view Blizzard misses a great opportunity to not only present itself as a company that cares but as one which preserves and extends the legacy of SC1. Lost potential. Let them fail here, they might eventually fail everywhere else - but the latter (pun intended) will only happen if the community stands up.