It's all a bit meaningless when in most cases a contract or permanent post has a three month notice period on either side. You are, kinda, safe for three months. When I was in GF for a short time as DE FO on the 767, there were one year contracts as DEC LHS on the 737, three year FO contracts on the 767. None of the 737 contracts were renewed. None of the 737 guys went to 767. If you went for FO 767, there was a good chance of upgrade within the three year period if you had previous Command experience. I left after 6 months (giving three month's notice ) but there was a period where, after much pressure from rank & file, to go "permanent". But, permanent still had three months notice on either side .
Following the 767 demise & very messed up handling , expats over the age of 60 were transferred to A340 on one year contracts (honestly) .
I don't know what Arab expat contracts were, Remember, they had non-Bahraini Arab expats in great numbers.
Boils down to the whole thing being very liquid and, of course, favouring management manipulation to their advantage. No change in Aviation management there then, eh ?