Even if they were, that's wouldn't be a problem. Spelunky looks awesome as hell and I've already played 4 Uncharted games, I don't really need another one.
That said, your point is valid. The execs aren't going to say "we don't need something like MGS/GTA/GoW Vita just because we've got Thomas Was Alone and Hotline Miami. And don't forget, Terraria is coming, so we're set!"
The real aggravation here is this:
People BITCH and BITCH and BITCH and BITCH and BITCH (well you get the point) about a lack of NEW IPs and NEW IDEAS. These things exist in ABUNDANCE in the indie community. Lots of people aren't going to go buy Hotline Miami in an indie bundle because they just don't think of their laptop as a gaming device... they'd much rather buy it on PSN/XBL or their phone or some other device. So Sony is pulling the indie love in, getting these developers to bring all that fresh content to us (just because you've played it PC doesn't mean everyone with a Vita or PS3 has). Yeah, it's not a big budget IP, but that doesn't make a game garbage.
You want fresh ideas and new IPs? Indies bring that. And just because indies are coming doesn't preclude any of the AAA big budget studios from making games. It can only help. More indies coming to Vita means more games for Vita owners to buy -- sales of Vita software will convince more indie devs to port games and develop for Vita simultaneously with PC and other platforms meaning we'll get Hotline Miami 2 at launch with the PC game. Whether you want indie games or not, you have to realize that you are not everyone else, there are people who want these games and will buy them (I can't say they'd buy a Vita for them, but if the library was right, they might). Strong software library, indie or not, can only help to increase sales. Increased sales means it's a more viable platform which could convince bigger studios to greenlight Vita games.
Any way you look at it, more indies is NOT a bad thing. And as VanWinkle and TipTop are saying: the idea that there's any sort of correlation between more indie games and less AAA is ridiculous.
Sorry to say but most of the people is just hypocrite, It's not true that people wants new ips or that gameplay is the most important thing, they say that just to look better(look at games like valkyrie chronicles for example, EVERYONE in internet say to love it, EVERYONE in internet say that they want more, reading all those comments you would expect it selling gazillions of copies, but you know what? It bombed hard, very few people bought it, and there are more examples). What people really want, the real system sellers, are games with a famous name and awesome graphics, this is the truth. There's nothing wrong in wanting this kind of games, i want them too and vita needs more of them, but people should just not lie about what they really want.