It is not clear from the answer - if you have downloaded photos that you are using and you cancel your membership do you loose the licence especially if it is the offer of 10 free stock pictures in the month that is free?
Branching to a new discussion,
Thanks for reaching out to the Adobe Stock community.
If you download all the assets prior to cancelling your Adobe Stock subscription, the downloaded images will always remain in your license history.
Hope this information helps!
Feel free to update this thread in case of any additional questions.