Except that all of this is in direct contradiction to the Death House Instructions PDF...?
This is copied directly from the Character Advancement section of the PDF:
"In Death House, there are specific points in the adventure when characters level up. When you get to the place in the adventure that indicates the adventurers advance to 2nd level, award 300 XP to each character and allow them to level up, as well as take a long rest. When the adventurers complete the adventure, award an addition 600 XP, which will bring them up to 3rd level.
It is important to note that this is different from standard D&D Adventurers League XP awards. It is okay if a character doesn’t necessarily play in every single session that you go ahead and give them XP anyways. For example, if a character plays in the first 2 sessions, but XP is awarded at the end of session 3, when they return, you can go ahead and award them XP. Likewise, if a character joins the adventure for the first time in a session after the XP has been awarded, then they must wait until the next time XP is awarded in order to receive experience awards. Either way, use your best judgement, and do your best to avoid ‘feel-bad’ moments."
Since this is in a document that is specifically created for AL use, wouldn't that mean this is one instance where the Milestone Rule IS allowed in AL play? Specific trumps General, after all.