The owner paid millions for this property, it is not going to just shut it down without a buyer lined up so long as it can keep generating some cash flow. Plus, there are probably lease clauses that tie rent rates to occupancy levels/foot traffic, etc., so getting new tenants in is important to prop up rent rates for existing tenants.
I suspect few if any of the new tenants will be national chains, but the owner is trying to get as much of the mall occupied as possible. That is a reasonable strategy under the circumstances. The death of a mall is usually a long slow process.
Yes, obviously they're not going to just shut it down. No one suggested they would. But the way they're going about it shows that they want to suck every penny they can from it as a mall and kick the can down the road as long as possible, keeping a slowly declining "status quo" rather than try any sort of reinvention or innovative approach to bring in more customers.
There's a pretty good chance the market value of the mall and prospective tenants/rent has declined significantly since they bought it in 2013. If the retail collapse gets worse in future years and if Promenade remains looking somewhat bleak/dated and a recession comes, they might end up in a situation where they have to sell it for quite a bargain due to massive waves of closures. I won't feel any remorse for a big NYC firm not willing to invest in making it better.