[1.30d]+[1.30 BETA 6] why don't "fuse" this versions to end the 1.30?

i mean, in beta 6 we can fight against mewtwo but in 1.30d we can't

that i want to say is why not finish 1.30 to go quiet(tranquilo google traductor) to 1.31 so u can integrate new stuff piece by piece transforming 1.30 into 1.31