Nintendo is ending Splatoon 2 Online Lounge support, but only on the Switch Online app starting July 28, 2021.
Ending Switch Online lounge support isn’t necessarily a sign of things to come, however.
The Splatoon 2 Online Lounge is how players set matches up with each other and is an essential part of playing Splatoon 2.
The Switch Online App is not quite as essential, though, at least not for setting up matches.
You can still do that through the game itself, and voice chat isn’t going anywhere
Nintendo Is Ending Online Support For Splatoon 2's Lounge Using the App
Nintendo will continue supporting Splatoon 2 voice chat through the Switch Online app, so players can still communicate during a match through the app — the only simple way to use voice chat in Splatoon 2.
Nintendo offered no reason for the change, though the Switch Online app is notoriously finicky and awkward to use.
It’s likely less to do with the upcoming Splatoon 3, since that game is at least a year away, and probably down to few people using the app to arrange Splatoon 2 matches.
[Source: Nintendo Support]