Could This Be A “likely Letter” From Northwestern?

I’ve heard about “likely letters” being sent to strong candidates, which are apparently unofficial acceptances from schools. I applied to Northwestern about 2 months ago, and just received an email about applying to their elite academic Integrated Science Program. It’s my understanding that such invitations are often indicators of a future acceptance…can anyone confirm this?
On a side note, during “Round One” of the college app process, in the fall during the Early Admission round, I applied to the University of Michigan and later received an email about applying for a certain scholarship, and was ultimately accepted to the University. Could be a coincidence, though.
Thanks for any input!