My lease on my storefront shop is up and will not be renewed. The landlord is Jewish. We had put up Mezuzahs. Must we leave them up? We don’t know who will be in the space next?
Essentially we may not remove the mezuzos when leaving an apartment etc. If however the next person to rent the space is a gentile, (or even a non religious Jew who is the type that will not respect the mezuzah properly) then you should take the mezuzas off the door. In your case, since it may be rented to a non Jew etc., but right now we don’t know, it is best for you to wait and see who the store is rented to next, and then you will see.
If the landlord is a non-religious Jew, and you are afraid that it will be rented to a gentile, you may take them off even beforehand.
Igros Moshe Y:D 1-182, Pischei Mezuzos 191 ftnt.19 in the name of Kuntres Hamezuzos.