Because if you do end up needing to rekey it would be much more expensive to change the electronic locks.

One of my places is managed by a PM and I've received notices for re-keying, however, the tenant was billed and paid; I was just being kept in the loop.  

give proper notice to enter according to local laws. show up with locksmith or drill through locks and install new ones. if place is empty, follow your local laws surrounding abandoned units. if unit is not empty, leave a notice that locks have been changed due to lease violation, and they need to contact you to get a new copy of the key.cost of locksmith or new lockset is charged to tenant.

If it is empty I would call a locksmith to change out the locks or do it myself.

No matter how much the rent is, it still costs the same amount to fix a dishwasher, repaint a bedroom, replace the coil on an HVAC unit, pay for quarterly pest control, rekey a lock, etc. 

Do NOT give them the check until they are gone and you have locked the newly rekeyed door behind you.  

I am slowly changing to the SmartKey system, so I can just rekey it.  

But that's a lot more labor intensive than "call a lock-smith"...  

They are sighting liability concerns and essentially by not giving me the keys forcing me to rekey or change the locks on the property thereby ensuring some contractor who made a copy can't break in after closing.  

Should I call a locksmith and enter the property?