I think not

as long as the species are used to bog

like some hardy Carex

some species Hemerocallis etc

freshly plants young plants are more vulnerable, but should be fine

and the ostrich fern and the pestasites could grow with longreaching rhizomes, with wich they rejuvenate themselves in a way

IME Phytophtora causes problems for fussy plants that encounter too much moisture due to a crazy season or some such

Short answer - no. As long as the plants selected prefer a consistently moist soil, they will be fine. And you can add to the collection with Iris laevigata or pseudacorus, Japanese iris, Lobeila cardinalis, Geum rivale, Gunnera, astilbe and a whole bunch of primulas.

Ok wasn’t sure if I step in my bog garden with the same boots I wear to work where I probably do walk over phytophthora infected soil would contaminate it. I saw these redtwig dogwoods at work and although I didn’t walk on their bed I don’t know how far out phytophthora or whatever disease it was was in the soil.

I would love more primulas but primula sieboldii(my fav one) is so hard to find! I currently have 3 next to my pond in full sun but still so small(divided this spring) I can’t divide them yet. Seeds are also hard to find