My tinfoil hat theory is he didn't get a copyright strike, but some other claim and he's just calling it a strike because strike sounds more dramatic. It might be someone issued a copyright claim, which can eventually be elevated to a strike, but is ultimately less severe. Basically, if this one random article I googled is still relevant, claims result in that portion of the video being muted, but the video also gets demonitized and future ad revenue it generates goes to whoever made the claim.
If it is a strike, enjoy the salt, but don't treat this as a death knell for Phil, he'll jump ship to Twitch (again). I imagine that's what this backup plan is he keeps mentioning. Not saying it's a win for him or anything, just don't want people being disappointed when this doesn't end in him being homeless.