First of all, what is your definition of a visual update? Since we've had some new changes to Malphite currently, which have been particularly small scale VU work and Riot could settle for similar changes if they deem Vladimir equally worthy. Yet that is hardly a 'traditional' rework so much as it's more a qol update, with no VO or splash art upgrades but plenty of VFX and model adjustments. Although these qol changes are just updates that ultimately puts the champ's inevitable full rework on the backburner for a much more extended set of time.
As much as Vladimir might become a candidate for adjustments like Malphite and Zhin Xao have, I'm actually hopping he doesnt. I'm arguing against these types of 'reworks', to me they deny the community the potential that comes only from VGUs or a VgU. Leaning more into a Vladimir VgU like which Morgana, Ezreal & Aatrox had. But that's just me.