As a general rule of thumb, companies that operate a loyalty points scheme (in whatever industry) periodically offer a sweetheart conversion deal. I have learnt to my cost that these often presage a closing of the old one!
With mergers and acquisitions, it is very much in the interest of the acquiring company to simultaneously ensure that the client feels that their points will all be honoured and to clear as many of them out of the system as possible! That said, the two companies are both members of Star Alliance and so they already have reciprocity of their FFM schemes. If they make a muck of it and you lose out, I would be VERY surprised.