Sure, we all would love global entry to be added as a benefit. While not out of the question, it seems unlikely that this will happen. The only cards that I am aware of that include this are your "true" premium travel cards, like Amex Platinum, Chase Sapphire Reserve, etc. What these cards have in common is an annual fee north of $400, and it's not waived the first year. I am not aware of any card in the $90 annual fee range to offer this benefit, which itself costs $100. All that to say based on market realities, it's probably not reasonable to expect this benefit to be added (unless, of course, it also comes with an annual fee hike).
I do understand that Global Entry costs $100 but it is valid for 5 years. I do not feel that a $20 per year perk is out of the question without a fee increase.
It works out to $20 per year over five years for the recipient. The $100 cost, however, would be incurred the bank all at once, however. Once paid up and admitted, the recipient has global entry for the whole five years, even if the recipient were to subsequently decide that he/she no longer wants to pay the annual fee and cancels/downgrades the next year. That's a lot of risk to take on an $89 AF card (which already comes/came with a yuge sign up bonus).
Plus, unlike a lot of other CC benefits where banks can benefit from scoring favorable prices with their buying power, Global Entry is a government program and the cost is likely set via administrative rule/regulation, so the cost to the bank to cover this will be a true $100.
So yeah, it would be cool to have it, but I wouldn't hold my breath. As competitive as this section of the travel rewards credit card market is, if it were possible to do what is being suggested, not reduce the signup bonus, not slash other benefits and not raise the fee...all while keeping the product line profitable...my bet is some issuing bank would have tried already. As pointed out by others, it would certainly be a solid point of positive differentiation within this card's competitive space.
I forgot the Chase IHG Rewards Club Premier card also adders GE/TSAPre credit with an AF of $89. Right now you can get 80,000 points after $2000 spend in 3 months.