In brief: If you've been saving your pennies for Nintendo's rumored 4K Switch variant, you might want to find a different use for them now. The company has come out to say, in no uncertain terms, that it has no plans to release such a product. The only new Switch model in the works is the officially-announced OLED version, which ships out on October 8.
This unfortunate news comes on the heels of recent reports that Nintendo had recently been 'supplying tools' to developers to assist them in creating 4K Switch titles. Judging by how fast Nintendo responded to the situation, It seems the Japanese gaming giant wants to squash any 4K Switch rumors before they can get any traction.
While it's possible that Nintendo still has something up their sleeves, it's looking a lot less likely that that thing is a 4K Switch. It could very well be a new console entirely---maybe a true Switch Pro, in the vein of the Series X and PS5---but it won't be a variant of the current-gen device; that much is certain.
We also want to restate that, as we announced in July, we have no plans for any new model other than Nintendo Switch - OLED Model, which will launch on October 8, 2021. (2/2)--- 任天堂株式会社（企業広報・IR） (@NintendoCoLtd) September 30, 2021
There are many potential reasons for Nintendo to go this route. The severe chip shortages the entire tech industry is suffering from is one, and Covid-19 related shipping delays and work restrictions are just a couple of others. And, of course, it's possible that the company just doesn't see any value in creating a 4K Switch. Perhaps it would rather focus its efforts elsewhere, such as on a new console, or its next blockbuster hit (hopefully) of a video game. Breath of the Wild 2, anyone?
Anyway, this information will undoubtedly disappoint some Nintendo faithfuls (indeed, it already has, judging by the reaction on Twitter), but most will probably agree that it's better to set expectations straight early on than let them fester. That is especially true when you have investors to worry about, as Nintendo does.