I haven't watched TNA since about June or July 2012 and I wouldn't be able to watch it now as Destination America isn't available. From what I understand, it's only available in about 50% of the United States anyhow, and I'm apparently part of the 50% that doesn't get it. So even if Bryan, Punk, Cena, Wyatt, Ziggler, and some others all magically defected and popped up in TNA, it wouldn't benefit me as a fan as I wouldn't be able to watch.
In the grand scheme of things, I don't think Daniel Bryan is going anywhere anytime soon. Even if Daniel Bryan never comes the "face" of WWE, he still has to be considered one of the top commodities of the company. While I personally think Bryan could pull off being the "face" of WWE, it's something I've never actually expected. When Bryan was about to start getting pushed as a singles wrestler after his team with Kane ended, I always surmised that Daniel Bryan would probably have a spot along the same lines as Chris Jericho. Like Jericho, Bryan has developed a reputation for being able to put together top quality matches with damn near anybody, he's highly unselfish, can be counted on to have fans interested in him and will probably remain around the upper mid-card level with occasional forays into the main event scene.
In terms of money, I don't think TNA can make Bryan as generous of an offer. Now while I can't say this is 100% accurate, I remember reading a few years back that Daniel Bryan has a downside guarantee of $675,000. Again, not saying that it's accurate, it's just what I've read. If it's legit, then that's the least amount of money Bryan can make with WWE under his current deal.