Failing any of that, and if one wanted to preserve the functionality that you had with the RTS, I suppose they could revert to installing just a simple local ('external') 'time switch' (in place of the RTS one) (probably electronic these days, rather than the electro-mechanical ones of old) - which is, of course, what millions of us had (rather than the RTS) in the past. However I don't see why they would do that, rather than fitting a 'dumb' dual-tariff meter like mine.