This announcement is disappointing, but certainly not surprising.
As has been discussed in this & previous threads, the current Saleen Corporation is not the same company that Steve founded back in the 1980's.
The company has been owned by a series of investors over the years who are viewing the products as any corporation would view them; profit centers. If those products aren't producing the expected returns on investment, then the investors/owners would be foolish not to consider other options to generate revenue. It seems clear to me that the current owners/investors are merely marketing the legacy created by Steve's original company, products & racing successes but have themselves no true enthusiasm for that legacy. Steve himself is merely a figurehead to be exploited for marketing purposes but obviously no longer has any authority regarding the decisions being made within the company that bears his name.
As I've said in several previous threads, the introduction of the S7 was the harbinger of the new direction of Saleen as a corporation & what they intended to emphasize as a priority. The continued production of Mustangs was & is merely a means to an end.
Remember also that Steve originally approached GM & in particular Pontiac about doing an aftermarket Firebird T/A conversion but was rebuffed.
The fact that FoMoCo has diluted their relationship with Saleen via the connections to Jack Roush & Carroll Shelby (to name just two) also plays into Saleen's decision to seek greener pastures.
However, IMHO it is doubtful that "Saleen Camaro" will attain the same status with enthusiasts or in the general marketplace as has the moniker "Saleen Mustang" over the past 20 some years. This is the kind of brand identification that no amount of corporate marketing strategy or $$$ can create; it is a spontaneous creation that occurs whenever a core group of people embrace something they consider unique & pass along their enthusiasm via a grass roots circuit.
As it is, this can only result in a benefit to the true Saleen enthusiasts who appreciate that once upon a time "Power in the Hands of a Few" really meant something other than just an empty corporate slogan.