Nintendo said earlier today that they're not working on an XL-style update for the Switch right now. That doesn't mean that other things aren't going on though. Thanks to some FCC filings from Nintendo, we can see that Nintendo is planning on reworking the guts of the regular Switch moving forward.
According to the FCC filings from Nintendo, the original Switch is getting a new processor and new flash storage chips. In particular, this was a “Class II Permission Change” with the FCC, which allows for tweaks to an existing gadget without having to go through the certification process all over again.