OK, now I'm confused. I have an LG 24" 4K Thunderbolt 3 monitor which plugs right into one of the four USB/Thunderbolt 3 ports on my 2018 MBP. Works a treat, keeps both itself and the MBP charged up. When I turn on the MBP the external monitor turns on as well. I've been loving this for the past nearly two years that I've had it.
So now..... Apple pulls a whammy and delivers new MBPs with an HDMI port and an SD card slot (neither of which I'm the least bit interested in) and only THREE USB-C/Thunderbolt 4 ports. If I use the Magsafe to charge the machine, fine, that leaves three Thunderbolt ports free for other stuff, but what happens when I plug in that LG monitor? It'll take up one of those Thunderbolt ports, for one thing, and I don't know if it will get confused and also try to keep both itself and the MBP charged. If I wanted to plug it into one of the Thunderbolt ports and ignore the Magsafe charging port altogether, no issue there except that again it's gonna take up one of the three valuable Thunderbolt ports, leaving me with only two and the stupid Magsafe port goes to waste..... Sigh.... I suppose I could just go with getting a hub and plugging stuff into that, which would leave the ports on the machine free, but I really don't want to do that. Thankfully, I've lots of time to see how things are going to work out for other people in the real world before I confront this situation myself in a few months, but of course I'm already thinking about it now.