The OGL remains valid. So material derived from the 1st edition Mongoose Traveller SRD can still be released. But there are two problems with this. The first is that nobody trusts Wizards of the Coast not to try again to revoke the parent licence. Such an attempt may not be legal based upon legal principles such as promissory estoppel and detrimental reliance. But fighting this in court is beyond the means of anyone else in the industry. The second problem is that Mongoose Traveller 2e is a better system than its predecessor. There are a lot of subtle improvements and enhancements.If you are publishing that stuff on DTRPG with the TAS license, that's no problem. It remains in force. What's still being addressed is new content derived from Traveller like Cepheus or things you want to sell that aren't via DTRPG as there is no standard license for those things currently in place.
If you want to publish material not based upon the 1st edition SRD or using content derived from the OTU, then you need a different licence to do so. The TAS programme provides such a licence. There are some restrictions on what you can do with it. And there is a royalty arrangement where Mongoose / FFE get a cut. But it's still reasonable.
The new open content programme is an equivalent to the old SRD based upon the second edition rules. Matt has indicated this may be use the ORC licence released by Azora Law. Creation of the ORC licence was funded by Paizo, but they don't control it. The ORC licence has different terms to the older OGL. But it is a perpetual and irrevocable licence. So it is on firmer ground. The main area of debate seems to be about the viral nature of this licence. If you release derivative content under this licence, some of your material automatically becomes available for other people to use. The details are in the licence itself. Some publishers love this and some hate it. Personally, I think it is reasonable that if you are using someone else's IP under the licence it is reasonable that you give something back to the community. But not everyone agrees with this view.