Oh it's still a thing, they just don't remark on it as constantly as they did when they were younger. They 'got used to it', basically. Being able to use that sort of sight is actually quite valuable when it comes to doing surgeries and anatomy studies, it turns out.
Vampires are not dying, no. They're a horrid sort of stasis thing, Amethyst coils and wraps around them regularly, but it is not the same sort of envelopment as a living person, where it passes through and out, it hangs unnaturally in place - clinging paradoxically to a being so close to the line of death yet not. There's actually a Blood Gift from Night's Dark Masters which directly has to combat this sort of thing - Aethyric Cipher:
Your natural mastery over the Winds of Magic allows you to cloak and dissipate the Aethyric distortions around you. Those with Witchsight observing you must make an opposed Will Power Test and achieve at least one degree of success in order to detect anything unusual about you. You are also immune to Daemonsroot, Witchbane, and any other similar wards.
Vampires, by their very nature as unnatural/natural Dhar generator/batteries, literally distort the Winds around them subtly by their very presence. They look like, to those with Witchsight, something fucked up unless they conceal it with effort or have the natural gift to do so.
Necromancers are also awful, pallid things, Shyish drawn through them and purposefully filtered and touched by the curdling, acidic, nastiness that is Dhar as well.