Sure thing!
To elaborate on this a little:
All projects in space(s) owned by your account, regardless of who they are authored by, count toward your account limits. You can see a list of all spaces owned by your account if you click your name/icon in the upper right to open the user popup, click "Account" to open the Account Overview, and then click "Spaces" in the header.
Note that if you later remove members from your space, you will have the option of removing the projects they authored too. If you do that, the projects will be gone from your space (the same is true if you remove projects one by one via the Projects list). If you do not remove members (or move projects), or if you remove members but choose to leave the projects where they are, the projects will stay in your space(s), regardless of your subscription status.