You can restrict this in outlook if desired:
https://support.microsoft.com/en-us/office/prevent-forwarding-of-a-meeting-8cd354e5-b319-403e-8dd2-88b8ee89b4dd#:~:text=When%20you%20create%20or%20edit,forward%20the%20meeting%20to%20others.
when scheduling a meeting
However, it should be pointed out that if the goal is to improve meeting attendance security, consider flagging the meeting for requiring authentication, and possibly registration as well so that the host can confirm all attendees, as even though outlook invitations can be flagged to prevent forwarding, it doesn't do anything to prevent an individual from extracting the invite URL and sharing in alternate means
We have a help article on the topic which is worth a read!
