The short answer here is no, not without your consent.
Retirement village residence contracts have the form of a loan/lease or a loan/licence, where you “loan” the village operator the money for the purchase of your unit and in return, they give you a right to occupy in the form of a lease or licence (read about the differences between leases and licences HERE). The lease or licence is a valid legal contract that will explain the ways the agreement can be terminated, either by the village operator or by the resident. The contract remains “on foot” or in place unless it is terminated by the resident or the village operator.
Sometimes a village operator may seek to change your contract. This would typically be a company-wide or village-wide initiative and usually not something targeted at you personally. The operator may seek to change your contract for corporate reasons (usually to get a better tax outcome – yes, I’m looking at you Lendlease!) or perhaps your village has recently been sold and the purchaser may want to align contracts in the village with their standard form agreements.
The village operator will typically incentivise you to accept the changes by offering some kind of reward to you personally or the village as a whole (say a new bowling green) and may even pay for you to get legal advice. Regardless of the reason, you must agree you any changes proposed.
The last word
Your personal position must be better off under the proposed changes. The government authorities that regulate the retirement village sector in your state would take a very dim view of new contracts that place the resident at a disadvantage to their previous agreement and would not support the changes.
If your village operator is proposing a contract change it is definitely worth entertaining the offer and seeking advice.