Actualy I don´t think to be that much outdated… exactly as you mention, if Rovals are 29,4mm outside, they should be optimal for GP5000 25mm as they run rather large… but 29,4 of the rim is still much more than the current norm, I don´t speak about Enve and such, but look at the majority of stock rims, majority is still far less wide than the new Rovals…
In my point view, I think I should not be forced to choose between aero and comfy set - common, we are in the 2020, for many years there are comfortable and decently aero bikes, why should I get battered and fatigued by a harsh frame during a demanding marathon race on less than perfect tarmac?