The question would only arise in the case of comms failure, when (if in IMC) you should follow your flight plan and not descend below MEA until you were in the hold pattern. In this situation, the question of whether you descend after the first pass of the beacon or the second is a little hypothetical frankly. OK, you could descend after the first pass as you are likely to be in the protected buffer zone of the hold pattern (unless wind is unkown and huge and you have not corrected for it). But most likely in IMC, with comms failure, and squaking 7600, you are not going to want to start descending until you are entirely sure that you are properly established in the hold and everybody below you knows it! I would fly at least a couple of holds at my filed en route altitude before daring to descend.
The question would not have arisen if you were in radio contact with ATC as you would have already requested and/or been cleared to descend to the lowest available hold altitude/level (above MSA) before arriving at the beacon.