As for the CBeebies logo, it has always been an arc shape, and the channel has never been referred to CBeebies BBC or BBC CBeebies. The BBC logo is only there for unified branding purposes.
The reason why the BBC logo is at the top is because of the brand new promo branding templates the BBC has been using, where the BBC logo is at the top, and the name of the channel is at the bottom, when the endboard is shown, both move into the middle.
The reason why the BBC logo is at the top is because of the brand new promo branding templates the BBC has been using, where the BBC logo is at the top, and the name of the channel is at the bottom, when the endboard is shown, both move into the middle.