IMHO, there is no possible release of new aircraft until v2.5.X is released.
My understanding is that ED is working as hard as possible to get this upgrade into place and most of the effort is to accomplish this.
While aircraft versions such as the F-18 are in the works, and third party new aircraft are being worked on, the major effort is to get 2.5 out the door, beta tested, moved into final release first.
Then, IMHO, we will start to see new aircraft arrive. PLUS - for an appropriate F-18 evnironment, carrier ops should be a must. I for one, would not be surprised if this element is also awaiting the v2.5 release. (Not to mention the strait of Hormuz).
Gentlemen: sequencing and time. Priorities first.
Cheers.