If the collateral requirement changes how could they keep working? The protocol version will change so you can't avoid upgrading and if you upgrade the transaction will not be a valid collateral.
You do not need to tell stories about changing the version of the protocol. In raising the guarantee deposit to 1500CRC there was no need. Perhaps tomorrow you will want to raise it to 5000CRC based on a vote of 46 people?
The artificial increase in the coin rate and the cessation of the work of at least half of the MNs is a very bad decision. I personally will sell all the coins and create one more MN on VIVO or ORE.