Third party games that are exclusive because of deals are almost always a timed exclusive unless the publisher is the the console manufacturer. This isn't just the case with this gen, at the very least it's been happening since last gen.
Actually, some bigger publishers are being more flexible when it comes to exclusivity this generation in the sense that they're letting the developers keep the rights to their IPS. Microsoft is doing alot of that, lately, with the whole PC-Xbone joint gaming platform they're trying to push, it's actually pretty cool. Nintendo is more tight when it comes to that but they have a good relationship with Sega since they make a shit load of money with that shitty Mario/Sonic at the Olympics. Plus Bayonetta 2 was an act of good faith from both publishers at Platinum Games.
Timed exclusives is also much more prevalent, like you said.
Lost World is keeping the Nintendo themed DLC so they have that going on for them. It's the new hip thing this generation. Exclusive fucking DLC.
