Of all the multitude of rules within BA, I have always presumed that the one rule known to all new joiners (be they DEPs, TEPs, CEPs), was that you go wherever the company sends you within your first 5 years period. Then once you are in, you learn “bid only for what you want”, but you won’t get it unless BA choose to unfreeze you. BA are hardly going to choose to unfreeze people where it would cost them money to do so. They do it when it suits them, and that is all. Some people have been known to do 3 courses within their first 5 years because they’ve been in the right (or wrong) place at the right (wrong) time. The great thing is, when you are eventually unfrozen, you’ll have lots of people stopping you from being bottom of the list.
There has been a little bit of talk about DECs, and bids like yours are precisely the reason why that will not be happening any time soon. All the while there are internal pilots wanting short haul commands, BALPA will insist they are unfrozen first, and I am sure there are plenty of frozen bidders available.