There are no exit fees whatsoever - Motley Fool Wealth Management would simply stop trading on your behalf, and you would take full control of your brokerage account. If you paid a flat-fee for Motley Fool Wealth Management's services, or have access to Motley Fool Wealth Management through your Motley Fool One subscription, and you cancel that subscription prior to the expiration of your membership for any reason, your accounts will be detached, and you will receive a pro rata refund of your membership fee.
Please be aware that transferring assets to another broker may require liquidations of the fractional equity shares owned in your account. There will be transaction costs and potential capital gains/losses associated with this liquidation.