This is a solid point and I'm inclined to want them to make something new and exciting that isn't the usual rote.

The problem is that what the fans want might be cloaked in nostalgia and a desire to return to familiar systems, but what it really is is a desire to move to a system that works well and is enjoyable to play. If SE had some brilliant idea that was unlike anything seen before and was actually good, people would be on board. The trouble is sometimes being original for the sake of originality is a bad idea if you don't get lucky and hit off on some brilliant new way of doing things, it's a disaster. I think Yoshi-P actually mentioned something to that affect in a previous Letter from the Producer. If you don't get it right it comes off as complicated, random and not nearly as good as anything that came before it.

So if the fan base just wants them to fall back on 'tried and true' that, to me, is a clear indication that they tried the high road of originality and novelty and didn't quite hit the mark. Not every new idea is a gem.

I won't be too sad if they fall back on some fundamentals that worked right and had no need to be changed (see: something as basic as a mail system) and then went forward from there developing new and exciting systems over time. Starting from the unknown and moving further into the unknown doesn't always work, but starting from the known and branching out into the unknown, at the very least, gives you a sensible anchor and core of satisfactory content that people won't take too much issue with.