Move a registered package to a subfolder of another package

Suppose there is a package A registered on General that need to be moved to a subfolder lib inside package B. If I understood correctly, after the merge, one should be able to find all the older versions after git clone repo B as the info on the registry will be modified to be the repo B.

What I have done is as follows. I used git filter-repo as in here on package A and then I did a merge following the steps here. The only differences from the steps in the git-subtree-merge here are that I set the remote to the local package A after applying git filter-repo --to-subdirectory-filter on A
and I also add the flag --squash in the merge command to prevent all the commits showing up in the new commit history.

The entire process looks like this:

 cd A
 git filter-repo --to-subdirectory-filter A
 cd B
 git remote add -f tomerge A
 git merge -s ours --no-commit --allow-unrelated-histories --squash A/master
 git read-tree --prefix=lib/ -u tomerge/master
 git commit
 git push

So, here is the issue. I follow the tests here to verify whether the SHAs for all the old versions of package A can be found in repo B. If I do that in the local repo where the merge happened, then I can find all the trees for the old versions of A. But, after git push to GitHub and then git clone. I cannot find the old versions in the new local repo.

What would be the correct steps to do for the package merge? Thank you!