It's a concession. Hootsuite didn't want to cover the credit card fees. But they ended up doing so. There wasn't even a proportional split (eg "let's each cover our portion of the credit card fees, according to our revenue share split") or a split of any kind. There was a separate concession by the vendor to cover steak dinners (of lesser value, and only a fixed cost) in exchange for Hootsuite's credit card fee concession... but that does not somehow make Hootsuite's concession a non-concession.
In any case, no point in debating terminology. Hootsuite gave up more value than they gained, but both parties got the deal done and are happy with it, so they made the right call in the end (conceding vs blowing the deal up). It's just not an amazing or widely applicable negotiation technique and, if anything, the vendor likely employed the better technique here.