No one who knows the "why" of "why do certain cars get certain software updates and not others" is going to ever answer this question publicly.
So, there is no way to know what you are asking, nor is there any way for you to know when you will get X feature or Y feature (just like all the other threads trying to ask various versions of the same "when will I get X update").
I would guess that, at least in part, one branch is more "experimental" than the other, related to the "advance" vs "standard" option in the car's menu.
Advanced would have features that might not be ready for prime time, either it isn't as stable as they'd like or even potentially removed. Standard would be stuff they're pretty set on and feel ready for the most part, barring unforeseen bugs.
I have my MYP set to advance and my sister has her MYLR set to standard. And there were a couple of small things that I felt like I went through, before my sister. For a while, we would leapfrog each other on minor steps within a branch. But recently, it was me on 2024.8.x and her on 2024.2/3.x. Now, I'm on 2024.14.6 and I'm sure she'll be getting a similar version too, following that assumption of the 2024.8.x branch being more settled upon now.
Of the games I play on Steam, there are a few that do something similar... an experimental branch for potential feature add-ons or major changes, and then a stable branch for everyone else that doesn't want to risk dealing with more bugs than necessary. Until the experimental becomes stable and they branch a new experimental.
Obviously, I can't say this IS what Tesla is doing, just being like everyone else is throwing a guess.