I don't think that will necessarily be the case, as the Nikon Z 14-30mm F/4 accepts 82mm filters without any kind of special set-up. Mirrorless lens mounts make wide-angle lenses a lot more manageable to design, so 14mm is possible with filters.My current 77mm filters can be used on my RF70-200mm, EF24-105 and EF16-35mm/4. CPL/6 stop ND and 10 stop ND are screw in and my grads are 100mm wide on 77mm thread.
Moving from my EF16-35mm/4 to RF would mean new filters for >77mm thread. That will be expensive for me. 82mm for the RF15-35mm/2.8 and would be larger if it is 14-35mm.
Unlikely that a 14-35mm lense would accept a front filter thread ie bulbous and need a special setup like the Nikon 14-24mm or EF11-24mm.
I have my Samyang 14mm/2.8 if I need wider but it is mostly for astrolandscapes ie not using filters
I'm sure that a new RF wide angle zoom will be great but it would add another AUD1k minimum for the new filters.... Much more if 150mm grads would be needed.
For my own uses, I already have all of my filters on 82mm and use a 82mm adapter on my 100mm Lee square filters, due to the 24-70mm f/2.8L II needing them already.
(Apologies that this a little off-topic on this thread!)