Actually what is happening here is very common for landlords that have failed to get tenants to sign all paperwork. Most likely when you signed the lease agreement the landlord or lease agent forgot to have you sign a specific addedum, such as the form mentioned in your blog question.
If you are planning on staying through the remaining lease, the additional form isn’t a big deal and won’t change anything if you sign it. However, if for some reason you break your lease early for any reason including loss of employment or a catostrophic accident; you would still be held to the full lease term. Otherwise, you may have some type of an out such as one month penalty.
Your landlord knows you need something from him, so he is trying to get you to sign an addendum before he complies.
Is it legal for your landlord to force you to sign the paper? There’s is no law that prevents him from trying to get you to sign the new addendum, however he cannot legally require you to sign it. If he is still being weird or pushy I would suggest filing a complaint with the RPA, or you could also create a paper trail by sending a certified letter to the landlord demanding that he provide you access within a reasonable time-frame such as 3 days from acceptance of the letter.
What your landlord is doing is not illegal, however, it is extremely unethical. He can’t refuse access to you for not signing his new addendum. You could actually claim that your landlord is in breach of agreement by not booking the freight elevator as outlined in the lease.

Man! That landlord of your sounds like a weasel. I’d file a complaint with the RPA just to prove a point. I had a landlord like this that was extremely hostile towards me. At first I was scared to file a formal landlord complaint, but then after I did– its like I’m renter from a completely different guy. He is very nice and we have an understanding with each other.
Even if you are planning to stay through the end of your lease, I would still not sign the paper. What a joke. If you don’t do the complaint, you should call him up and ask him what the form has to do with anything. Then ask him if he is refusing to book the freight elevator as outlined in the lease. I bet that would get him to schedule it. He won’t admit to refusing to schedule the freight elevator.

I’d just take the thing down the non-freight elevator. Your landlord is not working with him, so take it down the regular elevator. What a slumlord!