Tawnos
A guy with a bass
That's an argument I could buy, but let's be realistic here there was no coherent plan to accomplish any of this through first two movies and it really only happened when JJ Abrams decided to bring Palpatine back on a whim for the last movie. That's what it accomplishes in the end but it's about the shittiest way you could do it.
Also remember that when Disney bought Star Wars they had a much more aggressive plan for releasing movies, making it a bit more like the MCU with the idea being an annual release alternating between official 'episode' titles with a fillers like Rogue One/Solo/Kenobi/etc etc. I am extremely doubtful that they came into this with the Force Awakens planning to 'end' the Skywalker saga so they could move on.
I disagree, I think that was always the intention. The ST being a continuation of the OT was considered the smart way to bring Star Wars back into the public eye after a decade out of it, but I think Disney always wanted to ultimately move on. The rumors about the bigger trilogies that were supposed to follow the ST were always about something else, not about continuing on with the PT/OT framework.