I'd like to elaborate a bit more regarding the first suggestion I made.
In my opinion, usually the last duty of each expansion/MSQ progression still carries enough story in it, such as (spoiler alert) the Aetherochemical Research Facility (alo almost as lengthy as the current 3 duties in the roulette plus no loot), Baelsar's Wall, Ala Mhigo, the Ghimlyt Dark, Amaurot, the Heroes' Gauntlet, Paglth'an, etc. I personally think these cutscenes also worth watching, in terms of storytelling, and world-building. Why only protect the MSQ experience of the 3 Lv50 duties?
If we have to have unskippable cutscenes, I think if we could expand the roulette to include these content (or maybe include gradually as expansion updates as new players join the game), it could better serve the purpose of protecting the MSQ experience.