It's not conflicting. New evidence changes science-based understanding and decisions. This is at the core of how science works. It's impossible to know everything about everything immediately so you make the best decisions you can based on the information you do have.

Herd immunity is still the holy grail of dealing with an infectious disease like this. If new evidence says we're not going to reach it, for whatever reason, then you have to shift tactics to something else that may not be as ideal but is more likely achievable.

While I understand that messages/information changing can cause some genuine confusion, the concept that once information is delivered it must never change and if it does then you can't trust any of it is just a wedge used to sow mistrust. While it may be comforting to have that sort of authority/consistency, anybody who tells you they know everything about everything immediately is lying to you.