Well, none of the rest of us know what these other changes were (nor do we need to know). However, I have heard far more than one priest say that when one is put into a new parish, the unspoken advice is that the new priest waits 6 months before making any changes.
Since yo are well past that point of no return, people are going to sort themselves out,. Some will leave (and who knows where, if anywhere, they will go); some will go to another parish; some will hunker down and close off the pocket book, apparently on the mistaken idea they can punish the priest.
They are not punishing the priest; it is their parish and they are punishing the parish. Not that such a fact would slow them down, let alone change their minds.
And others will take to the new priest like a duck to water.
The same goes for priests who have been ordained longer - often far longer; but they usually have enough experience to know to go slowly.
As to the homily, I guess I would ask the naysayers when else and where else would be a good place to discuss it; and would they show? Would their friends show? Would everybody who comes to Sunday Mass at whatever time all show?
And the honest answer is… wait for it… NO!
I understand your concern. The new priest has moved too fast to make changes (6 months) and may have made too many too fast, even if he had waited that long. That results in unhappy people. And now this; so their are going to be (likely) more unhappy people, and some are going to be more unhappy than they already were.
Part of it may be how he handles each topic (assuming he addresses a number of them). One can skin a cat many ways; in the end the cat is still skinned, but some are more effective than others.
And part of the problem is that few parishes seem to ever have a “Come to Jesus meeting” on sexual issues, with the possible exception of abortion. So it is likely he is going to step on some toes, no matter how delicately he goes about it.
Take, for example, someone with a homosexual son or daughter, who has either a lover or a “married partner”. Likely, the parents already have enough anguish; and they likely are conflicted between not wanting to break their relationship with the child, while probably knowing that what the child does (as opposed to their inclinations) is wrong. That is not going to go down well at all.
Truth is truth, and needs to be spoken; but the repercussions can be enormous.
So I understand your concern. And the bottom is, there is nothing really you can do at all, except pray. You can speak to those who have confided in you, but it they are mad, it is likely you will not sway them.
Pray, and be very cautious of expressing much of any opinion; those who are not really listening may turn on you.