The typo would be inconsequential. Courts make decisions based on the reasonable intent of the parties. December 2019 is obviously not the intent of the LL by any stretch of the imagination.

If you did deny access based on the typo and then got an eviction notice based on non-compliance you would be hard pressed to defend your position because of your game playing.

Since you don't plan on denying the inspection and you some advance notice why not use some common sense and call up the LL and say "Hey, you messed up on the dates, what date are you coming to inspect." A judge will want to know why you didn't do that when you had the opportunity to clarify the inspection date.