Regarding
No More Experience Points: shrug. It was a long time ago I realized experience points are just pointless clutter. I'm going to level up when the DM deems it appropriate; everything else is just self-deception. Those checkpoints looks like a reasonable implementation; in a home game you'd just say "level up after about three game sessions" (or whatever).
Of course, in a home game things would get out of whack if you just sit tight back at the inn in the hopes you'll level up and out of the challenge zone of the actual adventure. But in practice, does that ever happen?
In organized play, it's not an issue. Sure, one group decides their own voices are more interesting than the actual adventure. But four hours later that's irrelevant (even if the DM was bored), and everybody goes on to new adventures.
Regarding
No More Gold in Adventures: I vehemently disagree "No gold in an adventure isn’t a big change". Not providing any "uptime" outlets for your gold is this edition's biggest failing, and "gold tends to just pile up after the first few levels" is an unacceptable problem that needs a proper fix, rather than resigned acceptance!
Just not doling out any gold is a huge cop out, and I'm sure the design team has underestimated exactly how fun people find loot and treasure awards.
Implement a proper magic item economy already!
Regarding
No More Magic Items in Adventures?: No this isn't bigger than "no more gold". Most people are already used to MMOs where you get "dragon kill points". I have no issue with this line of thinking.
My concern is instead those lists. Nobody will ever pick a quirky fun but ultimately circumstancial item if the opportunity cost is not getting a generally more useful item.
I hope the AL brass will realize they need to create at least two lists for each treasure type, especially the "permanent" lists (list F thru list I).
Standard stuff should go on the "A list": +1 swords, armor, rings of protection and the like.
Non-standard stuff should go on the "B list": the Tridents of Fish Command, Pipers of Sewage, Wands of Secrets, and Medallion of Thoughts of magic items.
And this list should come with a hefty discount. Perhaps -2 treasure points.
Actually, AL generals probably realize they have a massive bounded accuracy nightmare ahead of themselves if they don't do something about the specific stacking issues created by a la carte magic "shopping". Those paltry pages of XGE certainly luxuriates in ignorance...
Just to pick the most obvious example: +3 armor and +3 shields wreck games
+3 bows and +3 ammunition would have wrecked games if ammunition weren't insanely overpriced (if I understand things correctly you gain no discount in treasure points which is even worse than the already ridiculously bad deal of "half price" per the standard (gp based) rules).
Regarding
I think that treasure points can’t be saved up – they must be spent immediately that an adventure ends: while I think you are correct (XGE says you "must" spend your treasure points) it doesn't mean you're restricted to the points you just earned. XGE allows for "deposits" where you pay off part of an item, and when it's fully paid for you get said item.
Why they try to force players to decide what item to go for already with their first few treasure points, instead of simply saying "you can save treasure points but you can only buy a single item after each adventure", I cannot say. It appears to be added bookkeeping for very little gain...?