I fully support remaking old games and old soundtracks for the simple reason that the old versions will continue to exist regardless.
Also SoM+SD3 are two of my favourite ever games+OSTs even at my ripe old age and I'm glad about anything that will introduce more people to them. I am excited to play the new SoM, but I will take it for what it is. If it is inferior to the original, well, I wouldn't be surprised, but it will be fascinating anyway.
Do we know who is handling music arrangement? I am presuming it isn't Kikuta.