Indeed they do! I’ve noticed several elements from my concepts in a lot of characters that have come in over the years, like my Walrus and the Carpenter concept with the Swedish Chef (both hold an object to reduce incoming damage), gaining energy rather than doing a basic attack (my Cruella concept with Quackerjack), and even my Fairy Godmother concept with the actual character herself, to name a few!
Always makes me happy when either I, or other forumers, recognize their works being noted in official characters