The Switch is 20nm. This is borderline caveman age and probably the reason why they had to downclock it so much. They didn't have a choice because they bought off the shelves chips to Nvidia; If a hardware revision comes out, and especially if it's a slightly bespoke design, I fully expect it to be close to the state of the art when it comes to chip fabrication.
If we're lucky, X2 provides a satisfying upgrade for mobile and a smaller one for docked. Not enough to get the attention of a 3P that weren't interested before, but more than enough to market and push some new releases.
The budget option seems more likely knowing Nintendo's usual priorities. I think if Nintendo looks at the performance of the platform at $300 + $60 releases vs $170 3DS w/ $40 releases or 3DS vs 2DS performance, they would realize how willing consumers are to pay higher prices as long as the experience is a good value. Ultimately, Nintendo is selling hardware to sell their 1P games though. Their games will run fine on a Switch at the same spec. Cheaper hardware will likely expand software sales more so than a Pro line that would sell to people that already own the platform.