Dear user
Thanks for using Microsoft products and posting in the community.
Thanks for your description. I understand that you want to add people directly to an event without sending a reminder email, unfortunately there is no such feature in Outlook. In any case, an invitation email would have been sent to the invited person.
However, I think the feature you have suggested is quite good and I hope you can use the feedback feature in Outlook to send your suggestion to the relevant developer, thank you for your understanding and cooperation and good luck with your work.
Best Regards
Schale.P-MSFT | Microsoft Community Support Specialist