Out of the few 100+ threads that those Docs and Van Mol this is what I got from it. Since estrogen is necessary for bone health, mood, libido, etc. the more level of supression an AI has the higher chances of rebound. Rebound might not be the best phrase, but it seems once you start eliminating estrogen, like many things the body notices the deficit and try to create more than it did previously from pregnenolone/cholesterol. The more that's gone, the further the body attempts to synthesize more. Drop the AI and the phase where estrogen slowly comes back to normal and thre phase of the body attempting to synthesize more estrogen can 'overlap' before this process goes back to normal. During the 'overlap' estro levels can be too high in some people. Which's maybe why tapering seems to help :think:
Everyone's different and it doesn't happen to many people, but it does seem to happen. Probably the people who have hormonal imbalances, or even people who are gyno prone & have high estro levels since birth. People who should never run AAS but do anyhow. An example of this one idiot I know - he was 'toying' with the idea of running his 1st AAS cycle for a while. He had gyno at a young age but it went away as he got older and he decided to run Epi anyhow. Got gyno with while ON Epi. Used Letro to get rid of gyno. Ran 2 more cycles after, got gyno on both. Ever since before his 1st cycle, every person he spoke to recommended he not use AAS.