Are you sure you're not confusing your GH account with your IE account?
I ask because you never had 20,000 post to lose. You've never hit 8,000.
For years GoshenGipper's 8,133 frozen count led all members. He was followed by Jiggs and you, both in the 7,300 range. A couple of years ago ACamp and I passed those totals. I recalled that event as I received some gifts and reps from people remarking about the counts.
The IrishEnvy account opened by Svoboda, the original IE owner, has been an administrative account ever since posting automated messages to new members, auto posting daily news article, etc. Adding the 20,000 posts you think you've lost with the 7,368 listed with your account would give you less than 500 fewer posts that the IrishEnvy account which had been active for 2 years before you became a member and has been active for the 6 years or so since you left IE for GH.
Around the time of the GH disapora, one of the mods (fearing he could be held individually liable for the legal action threatened by Mike Frank's then website against IE and DD over use of premium material) did delete thousands of posts from the board. But his deletions were primarily in the Recruiting Forum (where some premium material had been posted by individuals). He deleted some individual posts and responses but in some cases he gutted entire threads only leaving the titles. Scooper, Jiggs, and myself each lost a few thousand posts that night as we had been frequent posters in the recruiting forum. As I recall you weren't a frequent poster there so perhaps you lost a few hundred posts ... years ago.
"20K", no way.