Anything is possible. But for calibre to implement something, someone capable of writing the code has to care enough. Typically that someone will care about the one or two devices they posses. Then someone(s) else have to implement it for the other N-2 devices. Then, yet another someone has to implement translation of the position scheme from one device to another. And then another lot of someones have to commit to maintaining the code as devices and sync schemes and ebook formats evolve.
Incidentally, the IDPF has actually developed a spec (EPUB3 CFI) for cross device epub syncing, unfortunately, as far as I know, calibre's ebook viewer is the only software that actually follows that spec, and that too, only because I thought it would be an excellent excuse to learn CoffeeScript. Like most of the IDPF's efforts CFI is hard to understand, let alone implement and was developed too late, so most ebook software developers resort to silly schemes like adding ids to every element (Amazon and Kobo are examples).