It probably won't work. Yacht Club is not considered a "Skyliner resort." The international gateway station follows Epcot hours, so you wouldn't be able to take the Skyliner to breakfast, nor would you be able to take it to rope drop Hollywood Studios.
We had the same problem in reverse, when we were staying at Caribbean Beach and wanted to take the Skyliner for breakfast at Trattoria al Forno. With Epcot opening late, we weren't able to board the Skyliner heading towards the International Gateway.
Said another way: What you're trying to do isn't considered "Yacht Club to Riviera," it's "Epcot to Riviera," and the Epcot line won't be running until closer to Epcot opening.