We did not block NMX received from bounty – you can still fully use it to pay for trading commission.
In additional, when we created rules of NMX token distribution, DeFi was not in trends. Times change and we change too.
Of course you blocked it. Can bounty hunters withdraw their tokens off the exchange? If the answer is "no," then its obvious they are being blocked from being in control of their earned funds. I for one would never deposit coins on an exchange that feels OK with changing their rules after the fact.
I understand you don't want the bounty hunters to all dump their tokens at once, but you should have included this language before the bounty began and not after it was all over with. It's also a bit weird that you are saying the "DeFi trend" is the reason why you changed your policy here. Your exchange's desire to chase this trend shouldn't negatively affect bounty hunters. You should just give them access to their tokens as promised.