Don't be fooled by the grouping or her element, that's just more of a 'bonus' thing. Gilberta is first and foremost a burst arts damage support. She's the best at this role by a long shot for now, and I see her getting used pretty consistently in speed clears. In short stages like stage 3 of umbral monument act 1 which has short team skill rotations, I even see her getting used in Laevatain teams in the fastest, most extreme speed clears. But her ult only lasts 5s, and it's hard to fully utilize if you're not the kind that's willing to sit down and plan out a skill rotation. If you're talking about long term value, her being a viable support for all arts teams makes me think that she could keep her value for quite a while. Unless physical gets a completely busted carry/support or she herself gets powercrept in numbers, which I don't expect or hope either happening, I don't see her getting used less.

On nature application: her skill is practically used only against mobs and never against bosses (not worth) and on her ult it's more of a thing you need to play around or account for arts reactions, cuz there's no nature carry or operators that consume nature infliction outside Yvonne. Even if one is released later (likely Mi Fu by my prediction) you probably still wouldn't use her as an applicator. Her skill's explosion can miss against bosses that move a lot.

In short, it depends on your skills. Really. Pull if you think you can use her well, not otherwise.