No, because the audience for such programmes is probably imessurably small. There's no reason, if extended footage even exists, that BBC Parliament couldn't show ITN elections?
They probably could, they could buy it like any other old programme. There are plenty of clips from 1979 available on Getty Images - https://www.gettyimages.co.uk/videos/the-nation-decides?collections=itn,itna&phrase=%22the%20nation%20decides%22&sort=best&license=rf,rr&page=1&recency=anydate&suppressfamilycorrection=true
- which they've made available for people to licence for clip shows. They've been used in numerous docs as well, like the one ITV did in 2015 and the great Swing Time in 1997.
But obviously the point of the election repeats is to tell the story of the election itself, rather than how it was presented. It would be a bit interesting to see the whole of the ITV coverage of 1979, for example, but the Beeb have already got their own coverage of that, and of course much of the footage is pretty much exactly the same. And as mentioned, the budget for BBC Parliament is microscopic.
Of course this summer this does appear to be an opportunity to compare the BBC and ITV coverage of an event, with the Beeb showing some Euro 96 programmes just after ITV have done the same.