Takui has been working with H!P for quite a long time (he did that one Nacchi song way back, for example) but lately they're really pushing him. I'm guessing, it's partly because of his increasing popularity thanks to MUSIC+ but probably also because Tsunku is sick and can't do as much as he used to. Tsunku approves of Takui as well after all, so as far as he's concerned I'm sure he's happy. Takui's been in business for a very long time and he's a musical genius as far as I'm concerned (though not Yoshiki level but still

) so it's not a bad thing. We get new flavor in H!P, Takui gets more work and the recognition he deserves and Tsunku gets to relax more (I'd hope). It's a win-win situation, really.
As for Takui's album, he said on MUSIC+ he thought of releasing it last year already so it's been done for a while, and judging by the story for Angerme's single I'm positive it's UF going "Hey we like this can ___ get to cover it?"