I mean, I'd argue we're already in WW3 and have been for some time. It's just mostly been various elements of hybrid-warfare as opposed to traditional kinetic war (at least up until Russia's SMO in Ukraine). We've already seen this war go kinetic in Europe so far, meaning I don't think his Russia prediction is exactly a bold prediction. They are about to go on a major offensive within the month after all.

That leaves the rest of the predictions that the OP made. China attacking Taiwan and US bases does seem a little dubious. From China's point of view they want to play the long game and wait us out as we continue to internally deteriorate due to social unrest and economic/financial collapse. I highly doubt they'd make such a bold move unless the aforementioned factors had already thoroughly materialized (which it will in the near-future, it's just a matter of time before the dollar's strength is weakened sufficiently).

As far as NK attacking SK yeah I highly doubt that is happening any time soon. North Korea mostly exists to be the never ending boogeyman rather than to inflict any serious harm to their neighbors. I'd be surprised if they became bold enough to actually assault SK but who knows. Anything's possible I suppose, especially if things continue along this trajectory. Still, I'd say it's highly unlikely.

As for Iran... I feel that their prediction here is a toss-up. I'd err on the side of unlikely but after Israel directly attacked them just a short time ago I wouldn't put it past them to finally punch back.

All-in-all this is likely anon fear porn however I wouldn't be so quick to just dismiss this scenario as far-fetched. There's a decent chance this could quickly spiral out of control once Russia's offensive plays out. It really depends on the Western response to the situation. If Washington comes to their senses and strikes a peace deal with Putin and quickly pivots back to Asia to contain China then this could be avoided. However, if our insane warhawks insist on doubling down to confront Putin directly with NATO troops then I'd say this scenario could very well happen.

How Ukraine plays out in coming days will be the deciding factor imo.