If you make a big change in the community, members will complain.
Even if it improves what came before, members will complain.
This doesn't mean you've done something wrong, it's more simply the natural human response to change. You're fighting against system-justification theory. Members will typically defend the status quo (when if they don't particularly like it).
The danger here is you make a big change in the community, receive a brutal negative feedback, and decide to change back. This prevents you from guiding the community to where it needs to go.
There are steps you can take. You can let members know about the change in advance, involve members in the change, and frequently seek their opinions. However, you're still likely to face a negative impact.
This means you need to appreciate that you will face a negative feedback in advance. You need to ride out this storm. After the first month, see what your data tells you. Over time, the new changes will become the status quo.