4k confusion

I'm confused. 1350 is a dedicated 4k channel now but no 4k content shows here since the Olympics. Why do I have to still use the "on demand" version of the 4k stream.

Speaking of which. Last night's Phillies and Padres games were available in 4k on YTTV, Fubo, Fox Sports App, but not Comcast. Why? I have my thoughts why but I'll let that be. What's going on?