Minor quibble with this. SEAD is a combat tactic which assumes you're already at war and suppressing defenses to advance a specific mission. A no-fly zone is a strategic patrol. It tells the enemy that you have overwhelming air superiority within the theater, and it assumes the enemy isn't willing to risk testing the no-fly zone. In the past no-fly zones have been more or less declared and imposed, and actually SEAD missions were unnecessary.
To be sure, actually enforcing a no-fly zone could require SEAD missions, in which case, it's not so no-fly. But yeah, it's still a dumb idea here, and it could provoke a wider war.