Probably not at first glance for every user. I still have Sync for Reddit installed and both Sync for Reddit and Sync for Lemmy show up as "Sync" in my app drawer, the only difference being that the latter doesn't have an icon pack theme applied (though I think the difference is SR = white and SL = dark).

There's probably an extremely tiny minority that doesn't know that SR died, had purchased Pro or Ultra, downloaded SL without knowing that SL is a "reboot" for Sync, hadn't noticed that Lemmy isn't Reddit, and then tried to restore their purchase expecting it to work. But I don't think it would be inherently obvious how it isn't the same app once it is installed on your phone, since it appears to work identical to the original Sync