This is a big deal for a couple of reasons.
One is that there has long been a coterie of conservatives who say "there is no difference between Republicans and Democrats." When McConnell said he'd hold up Garland's vote, those people said that McConnell was just posturing, that he'd cave after the election, etc. That he was really in league with the Rats all along. But he didn't, and Garland wasn't confirmed.
Then they were convinced that he'd cave if the Democrats threatened a filibuster, and he'd force Trump to nominate someone much more liberal. But he hasn't, and it sounds like Gorsuch is going to be confirmed, even if it takes the nuclear option.
That doesn't make McConnell a paragon of conservatism, but it does illustrate that there are significant differences between Democrats and Republicans overall.
The other reason is that it is going to get Gorsuch seated in time to participate in the last part of the term, which means he'll be able to hear some cases that will be based on some of Trump's orders if the Court decides to hear them. That's a pretty big deal as well.