After you copy the Wordle post, you can use this shortcut, then paste to the forum as usual.
It takes the clipboard and replaces all the symbols that don't post with ones that will. I tried to preserve the color and shape of the original, but eventually gave up. I couldn't find a group of aesthetically pleasing symbols that all worked. So, I ended up with this, less colorful, solution.
I've only used this on my MacBook, so if it does not work on the iPad let me know.