It's a fair assumption. It might turn out differently though. It's not as doomed as the Wii U port scene was; most companies just threw their PS2 teams at it and then when that market dried up they all packed it in.
just to clarify, me too I think that it's fair to think about struggles for the Wii U in getting a serious third party support, as I stated also few pages back to who was foreseeing Wii U selling like crazy.
I just think that if Wii U will get a similar third party support as the Wii, I'd be negatively surprised, for several reasons.
(Premise: I'm not imagining a HUGE third party support with big esclusives for the Wii U. Keep that in mind.)
1) Wii U is the Wii's successor, not GC one. Wii was ignored at the beginning because everyone tought that PS3 would have been as successfull as PS2, while GC was almost a failure. It would be way more stupid for third parties to ignore the at least the first part of the life cycle of the Wii U, especially in Japan (and the first part of the lifecycle for Nintendo consoles is absolutely the most important), compared to the decision to skip the firt part of the Wii's lifecycle
2) Wii U will launch now, that means that for one entire year it will be on the market without the new PS console (I'm assuming that also next Xbox product will be ignored by the Japanese croud); it could offer a very simple way to have multiplatform titles with PS3 (as Koei is doing with Mosou games, for example) offering two viable platforms for the Japanese market (considering how 360 is dead over there)
3) Offering their own classic titles also on the Wii U could help them in getting good numbers with multiplatform titles on PS3U also at the beginning of the new "PS4 era": we saw how Sony's platforms, if developed with their recent business model in mind, could struggle in their first period on the market (they need time to penetrate the market, opposite to the most recent Nintendo's consoles with a different business model), so it could be smart to exploit PS3U also in late '13/early '14
4) Third party relationship with Nintendo are growing gen after gen (at least in Japan), with big franchises debuting on the Wii (as Monster Hunter, but also Samurai Warriors and Taiko), coming back (as Dragon Quest), or continuing with more efforts (as Tales of). I think that presenting a console that offers a more classic way of playing (allowing for more classic approach, if necessary) and continuing with deals (as the western publishing/distributing processes for key Japanes brands that usually struggles in the West) could grow the relationship a little bit more
5) The only reason that could push third parties in ignoring the Wii U imho could be the fact that Wii wasn't able to get great numbers for some kind of games, and this could happen again of course; but we know that one of the main reason was also the lack of a certain kind of offer on the console for more three years (while other competitors offered various products aimed at a certain demographic)
So, I'd be surprised to see a Wii U third partyy support exactly identical to the Wii one for several reasons (and among them, the way better start/debut of third parties for the Wii U launch compared to the Wii one: not saying that it is huge or spectacular, and it also has less games; but there are more important brands/genre on the console from the beginning)
My 2 (4? LOL) cents