I think Spain’s motivations for doing this is two fold : 1. There own remote working policy since lockdowns have eased has not continued at the same rate as other countries. Read more...
...g-of-the-future.html" rel="nofollow" target="_blank">https://english.elpais.com/economy-and-business/2021-11-08/why-remote-working-in-spain-is-once-again-a-thing-of-the-future.html
And 2. They need our spending power adding to their local economies. It will stimulate growth again in the property sales, rentals, leisure and travel just by attracting UK taxed pounds to be then spent in Spain reading 21% tax for every € spent on travel/ retail/ leisure etc.
I can’t see it not happening, makes good economic sense. For me, provided my agency umbrella company agrees to me working in Spain up to 6 months each year, it prolongs my work life - win’win all round. If I take the remote visa that’s an extra two years of possible work and I can defer the old pension.