Apple discontinuing the 2023 Mac Pro without a follow-up makes them having announced it to begin with all the more puzzling. If you weren't going to update the damn thing, and you weren't going to charge a more competitive price, let alone charge $3000 over the Mac Studio equivalent and only provide PCIe slots that can't accomodate GPU boosts or upgrades and two extra Thunderbolt ports as a feature bump, then what the hell were you even releasing it for?
There were better ways to market that Mac such that folks would want to buy it and they just...didn't do it.
If Apple had planned to move to an M5 Extreme or some other upper tier Mac SoC, the M2 Ultra Mac Pro would've made some sense as a transition product. But to be the last one? It was a lame note to end on and I think it would've made way more sense to just end it with the 2019 model; especially if the whole idea is that the Mac Studio is the future. Hell, they could've launched the Mac Studio with a Thunderbolt breakout box, left the 2019 Mac Pro to be sold up until 2024 and then cut it off there and it would've made way more sense.
Now that we know how the Mac Pro's story ends, it really deserved better writing.