There certainly a lot of options to accomplish this. You also have to wonder about why they are doing it now. Certainly they are overhauling the entrance, so it might make sense to work it in now. I have to believe a pathway was envisioned ages ago, and it just got shaved off for budgetary reasons.
I don't think the electric water parade is any sort of limiting factor in implementing the path despite it's sentimental value. It could be stored elsewhere. The floats could certainly be made to fold down cheaper than the cost of a draw bridge. Getting the riverboat out is the bigger concern.
For me, I think this is smoke that is leading to a bigger fire. It's not a project worth the effort by itself. Maybe it's just a tag along of the MK entrance overhaul, maybe there is more. I thought there was once rumor of a parking structure near on the GF side of the canal that would allow folks to walk to the park?
I could also see them doing something like the Cornado, and put up some sort of bridge/boardwalk type of deal with a restaurant/bar.
Whatever they do, I think it's a pretty valuable chunk of real estate between the GF and MK, I'd be very surprised if a path was the only goal here.