Here’s a terrible solution…
I was also looking to find a “join through edit” feature in Premiere Pro; the reason is I had created all my cuts on the wrong clip (the one above the one I was actually working on). Solution: I simply selected all the cuts I’d made except the first one and deleted them. I then went back to the first cut and dragged it out to the end making it one single clip again.
Terrible, but it worked.