Old contract still recognised whilst waiting for new one?

Hi all,

Ive agreed with my new landlord to change our move in date. Ive already approved it on openrent and im just waiting for the new contract to be sent over.

Im wondering, does the original contract still remain in place? It was signed by all parties.

Its just that, as im waiting for the new contract. I do feel a decreased sense of security over the property if the last contract no longer bears any significance.