I would certainly use it again, more a question of how, and we had a question before of reusing the same compost used for flowers, to grow salad:
Best results will come from replacing it, depending a little on the vigour of last year’s flowers. Why not do a comparison between replacing and top dressing with new compost? I have tried both for salads and am not convinced either way.
It is certainly of value as top dressing for your vegetable patch.