Of course it's possible to change yourself. But it would make more sense if it was removed automatically, plus I wouldn't suggest editing it for users who don't know what they're doing.
That being said, Microsoft has mentioned that the bootloader entry is only temporary anyway, and that in future builds, it'll be part of the recovery environment and not a specific bootloader thing, so I guess it'd probably be a waste of effort for them to have disk cleanup remove it when it's a temporary thing anyway.