Presumably if current scheduling patterns continue the final Pages from Ceefax on BBC Two will be in the early hours of Monday 22nd October, and the first airing of whatever replaces it would be the early hours of Saturday 27th.
Pages from Ceefax is generated 'offline', there's no reason it couldn't continue past DSO, even if it's just for a bit.
What could they replace it with anyway? Maybe they should put the same content onto a PowerPoint presentation, similar to ITV Nightscreen.
"Page from BBC Red Button", anyone?! (After all, red button is basically the digital TV equivalent of Ceefax)
Clearly, a bit like the PowerPoint suggestion, a specific "on-view" version would have to be especially generated, as the box usually housing a shrunk-down version of the channel's live output would be redundant (this could perhaps be replaced by article-specific stills? Or just have a different layout, without such a box?), as would any text etc stating that pressing numbers and/or the blue/green/yellow buttons will do anything (some/all of this could be replaced by text stating "press the red button for interactivity with this service" or similar).