Honestly I'm a subjob BLM player and not the kind of player who tries to dig the job to the deepest, and I never systematically learned the theories about non-standard versus standard. From such a non-top player's view, I have no idea how deleting ice paradox and forcing players to do the standard make this job more popular. (Contents below are some of my own opinions, might be wrong.)

I can understand that Yoshi'P the Producer wants BLM to be accepted by more players, yet from what I know so far, the reason people refuse to play BLM in raids is not those theoretical differences among rotation structures, but the fundamental-skill requirements/the over-high penalty of Gcd losses/frustrating Enochian suspension.

If the producer expects more players are trying to play BLM in DawnTrail, a good direction could be working more on mistake-solving! Every rookie BLM makes huge amounts of mistakes when practising. Simply limiting the rotation to standard will not benefit them, but on the contrary lower down the flexibility(the best part of BLM).The new FireIV gauge in Dawntrail seems to trigger the player to finish the standard perfectly, if failed, the frustration grows even stronger compared to Endwalker.

One typical BLM mistake is that the player incorrectly starts to cast a spell (Fire IV,Despair, Flare, or whatever) when the fire phase duration isn't enough. In such cases when the player needs to interupt, a Endwalker BLM can use either a firestarter(if available) or a Transpose-Ice Para as a good way to avert the potential loss. Ice Transpose can both hold up enochian and provide extra instant cast skill to do mechanics, even though it might not be good enough and might change the whole rotation, but those feedbacks of adjusting successfully are truely positive. For a Dawntrail BLM, player can only use the firestarter provided by paradox, if not available, any other solution(either casting low pot Blizzard Ⅲ for mp recovery or transpose back to fire with unfull MP) brings strong penalty and frustration.