Should move this to products!
If it is a batch, then no. Trigger then maybe.
You will have to run it again. Or create a new smart campaign.
I would do it like this:
Add them to the SFDC camaign.
Create a smart campaign, smart list is Member of SFDC campaign, then add another filter saying Was not sent email = "invite"
Then run that. But watch how many leads qualify, it should be approx the number of leads you added to the campaign.
PS your boss sounds mean, to leave you in the dark like that! ha.