I don't mean skin everywhere is exactly the same, I mean that in the same way that estrogen benefits vaginal skin (moistens it, plumps it), so it does the same to facial skin. (And all skin.) That's why one of the symptoms of menopause is dry skin - not just in your vagina, but everywhere - and often itchy as a result.
If you google 'estriol cream for the face', you'll get up multiple products. Estriol isn't absorbed systemically, there is research which shows that. It's why women with histories of breast cancer can have local estrogen in the vagina.
The only thing I'd say about estradiol (Oestrogel) on the face, is the alcohol in it can be quite drying so needs to be well moisturised afterwards. As I am basically bathing in gel every day, putting a bit extra on my face doesn't really make any difference. But if someone was on a very low dose or very sensitive, Oestrogel on the face might well not be a good idea. Estriol, on the other hand (Ovestin) should be totally fine because it's not systemic.