I think so too. Especially if the initial infusions are normal length, ie a few minutes. I think the liquid changes its alkalinity by the third or fourth round. Not good for weaker stomachs, nor as tasty anyway.
Rebaked oolongs, black and puer teas stands a bit better than white, green and green oolongs in this respect. Gongfu style infusion, where each infusion is much shorter, there can be a lot more rounds.
