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 communication 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.
I do a lot of presentations and I sometimes use that phrase, but not in the way that is described here. I use it when it’s accurate (i.e., I had to do a presentation that covers a lot of material for a group of people who are new to the topic) as a way of A) respectfully acknowledging that people may be feeling overwhelmed or intimidated and B) inviting questions and requests for clarification. As in, “I know this is a lot of new information, so is there anything you’d like me to go over again or questions I can answer? If you prefer, you can talk to me after one-on-one or send me an email.” I also always try to provide written handouts/summary notes beforehand so people have something to refer back to.
I believe you that there are people who use this phrase to shut down questions or dismiss confusion, but it still seems odd and counter-intuitive to me because if you are a presenter and you know that you’re giving people a lot of information about something, you should be even more considerate about making sure they have genuine opportunities to take it in and understand. I will keep this in mind if I say such a thing again though in case it does come off this way.