^^^^Definitely my thinking as well. It certianly was plausible to think that Riker would turn down a small command to be XO of the Federation flagship. However, that has the look of something that started as an afterthough, throwaway type line that morphed into something that came back to haunt the writing staff.
It is worth remembering that Patrick Stewart was a controversial choice as Captain and that there was no guarantee he would be back for season 4. It's almost like there was an assumption that Stewart wouldn't last and all of a sudden everyone was scrambling to catch up when it turned out otherwise.