Sometimes presenters try to reassure their audience by saying “I know this is a lot to take in”, or “I know this is a lot of new information.”
That tends to backfire, because it comes off as condescending.
It can also send the message that it’s not ok to disagree, and that if you disagree, the presenter will take it as not understanding what they’re saying. This is particularly the case in religious presentations and political presentations about privilege.
It can also send the message that you’re not expected to understand and that it’s not ok to ask for clarification. And that spending the whole presentation really confused is an acceptable outcome.
Your goal should be for your audience to understand. Confusing your audience isn’t a virtue (unless sometimes if you’re showing them that a topic is really complicated, some amount of confusion in an arc of communicaiton can be ok. But it’s important that understanding and clarity be the goals.)
The point of presentations is to teach your audience something. If your audiences regularly fail to understand your presentations, that means that they need to change in some way. Saying “I know this is a lot to take in” isn’t a solution.