You export everything, then it is deleted. The brain is your asset: facts, sources, and history leave with you in structured form, and the tenant is destroyed on the schedule you agree, not held hostage.
Lock-in by data hostage is a real industry pattern and Heidi rejects it on principle. A company brain you cannot take with you is not yours, and the whole pitch is that it is yours.
Practically: request export, receive your memory in structured, machine-readable form, confirm, and deletion follows. The deep answer on export is at falkster.ai/answers/can-i-export-my-data.