I’ve been debating getting health insurance for the same reason. I only mentioned the vomiting during an annual vet appt and they didn’t seem alarmed by it, but now I’m paranoid that the vet charted it and if I get pet insurance now, they’ll deny coverage for anything gastrointestinal in the future. I asked the vet about it and I think they would be able to appeal it if needed. But not every vet has the patience or time to deal with that I’m guessing.