I’ve gotten a couple in the past few months, and it definitely seems to be a thing/have been a thing: https://www.howtogeek.com/721043/why-youre-getting-so-much-signal-spam-and-what-you-can-do/ https://www.androidpolice.com/signal-is-taking-the-fight-to-spammers-with-new-message-requests/
71 on Metacritic, 6.8 user score. Not bad! Will definitely be getting it if it works well on Steam Deck.