Preheat oven to 425°F. Heat two large sheet pans inside while the oven warms.
Toss frozen fries with olive oil, salt, pepper, paprika, and garlic powder in a large bowl.
Spread fries on the hot pans in even layers. Bake until starting to brown, about 15 minutes.
Melt butter in a small saucepan. Whisk in hot sauce to make a smooth Buffalo sauce.
Toss shredded chicken with half of the Buffalo sauce; reserve the rest for drizzling.
Flip fries and bake until deeply crisp, 8–10 minutes more.
Pile fries onto one pan. Top with sauced chicken, cheddar, and Monterey Jack. Drizzle remaining sauce.
Return to oven until cheese melts and bubbles, 3–5 minutes.
Finish with blue cheese, bacon, ranch, green onions, and parsley. Serve immediately.