Things with Rey and WWE did not end on the best of terms. The Wrestling Observer newsletter reported several months ago that Rey was not happy about the company extending his contract for being out of action with injuries.
Konnan has publicly talked about wanting to get Rey in with Lucha Underground and Rey did visit the set of Lucha Underground a few months ago. The deal, as of this writing, with Lucha Underground has not been signed yet.
Also, as we first noted earlier AAA announced that there will be a press conference in Mexico City. That will likely include the announcement of Rey Mysterio signing with the promotion. Since his contract technically expired, according to WWE, he is free to work anywhere he wants and there is no non-compete so he could show up at the Rey de Reyes event on March 15.
There are several independent promoters already looking to get in contact with Rey’s people. One thing they should realize though is that his price tag will be very high. I would guess that he would cost more than any of the recent high profile free agents that are available right now.