It might depend a bit on who you're building with Penny. I asked Selkirk about it the other day and they confirmed that the bricks were in short supply at the moment which is why some builders have pulled specific bricks out of the selections, but said that if I was building with M and only at contract-signing stage, there shouldn't be any problem.
Pity you had to upgrade, CiNny - are you pleased with your new choice? At least now you can be sure that you won't be held up by the bricks.