An agreement to change your rent does not terminate your written lease. Thus, the notice requirement is likely still valid.
I hope this information helps answer your question(s).
~ Kem Eyo
The above answer is a general explanation of legal rights and procedures. It does not constitute legal advice. Nor does it establish an attorney-client relationship between the individual posting the question and the attorney providing the answer.
Generally, a written contract can only be changed by a written modification and not an oral modification of the terms of the agreement. Any verbal modification made in the written contract is most likely void if both parties did not agree to the modification and the modification is not in writing. Thus, the terms of the original contract will most likely be enforced.