Odds are that the answer given to you above, as well as the position now taken by your landlord, are wrong.
You can bind yourself to a lease for its term -- so there could easily be a provision in a lease making plain that you are responsible for your share of the rent through the conclusion of the lease term unless properly released from that obligation before the end of the term. However, you are speaking of ending the lease at the end of its presently month-to-month term. It is simply not the case that you are forever obligated to renew an expired lease and pay a share of the rent as long as one of your co-tenants wants to renew.
If there is language in the lease that speaks to your continuing obligation for renewal periods, you should quote that language for us or show it to a real estate lawyer in your state.
Is this a separate agreement from the lease? Is the landlord a party to this agreement?Quoting elerodgers
I am skeptical that this agreement creates a perpetual liability upon you unless and until all roommates agree to decline renewal, but as with the lease we are not in a position to interpret contract language that we have not seen.
If the landlord accepted the notice, the question is raised as to whether the landlord can later revoke that acceptance. A landlord can release one co-tenant from further liability under the lease without the permission of the other co-tenants; but depending on the terms of the lease, doing so may affect the other co-tenants obligations to the landlord.
You are in a poor position to snark. This is not a question about joint and several liability for co-tenants during the tenancy. This is a question about whether and when one co-tenant can end the tenancy.Quoting latigo

