Really? At my workplace if we had a vendor email us about needing to take some action to continue being able to work with them, but we didn't follow through with that, any business disruption would be squarely on us for not handling it. At the very least even if we can't meet a supposed deadline, we need to work with the vendor to get extensions if possible, and if that's not possible then we either need to mitigate the impact or get more resources on the changes ASAP.