To be expected really. Did BBC Choice have any new content before 7 before CBBC on Choice started?
Originally they started at about 5ish on weekdays and about 1 on weekends.
It used to open up with an Australian soap opera, something Beach. At weekends there were children's programmes, mainly archive such as Rentaghost and some linked by 'The Dog and Dinosaur Show' - Dog and Dinosaur were animated characters done by early motion-capture type technology
The channel numbers will be the same as usual. CBBC normally has the daytime hours on BBC Three's frequency, so it's that what will effectively take Parliament's daytime hours. Parliament's channel number will just broadcast the standard red "off air" caption used during BBC Three, BBC Four, CBBC and Cbeebies downtime.
CBBC and BBC Three appear to share the same transmission material (cue times when the CBBC DOG has appeared on BBC Three programming) so I presume there's a spare transmission "system" to run BBC Three all day and CBBC at the same time and feed the DOGs?
Of course this might be testing the waters for an extension of BBC Three's hours to see how it goes down. Looking at the schedule posted above, I think we can say it ain't gonna happen any time soon as even Total Wipeout repeats are now shared between BBC Three and CBBC.
Extending BBC3's hours permanently wouldn't really be worth it. ITV2 and E4 both pick up the bulk of their audience in the evening and are both full of repeats or cheap imports during the day. BBC3 would end up the same way, but because they're only on air for 2 hours pre-watershed, most of the repeats would either be on a constant loop or they'd be 'stealing' shows from BBC1. They'd be criticised for not being value for money which is something the channel already faces, not to mention the problems BBC2 daytime is currently experiencing.