Keep in mind that if your company has a lot of high-earners and these high-earners are the decision makers in this case, they may not find the FICA savings that appealing because they may personally be in a situation where they only save on the Medicare portion. In the case of most highly compensated employees, their effective FICA tax rate is 1.45% each for employer and employees, since their incomes generally exceed the ceiling for the 6.2% (each) Social Security component of the payroll tax. The ceiling, which is adjusted annually for inflation, is $132,900 in 2019 (up from $128,400 in 2018).
Also, the company would have some unfront implementation costs to establish a payroll feed from their payroll system to the HSA plan of choice and a decision of whether to pay for the monthly admin fees for each employee who opens an HSA, or have the employees pay the HSA admin fees via a monthly deduction from their HSA account. Since some employees drain their HSA almost immediately once money is deposited, the HSA administrator often requires the employer to be on the hook for those fees in the event the employee does not pay. These are somewhat hidden from the average employee experience.
I do encourage you to bring up the topic with your HR team. The more employees express an interest, they more they will take it seriously. Perhaps they'll add it for 2020 if you keep bugging them about it.
How many people work for your company by the way?