It is better that the posts stay when someone leaves even if
it is with a different number. There was a time that you
could delete the posts but that was changed. You probably
remember Invincible she had so much great information and
she deleted everything with the result that some threads became unreadable.
It is too bad you are not able to search your new number,
I did not know that.
I feel it is good at least you are able to change to a number because some people prefer not to be recognized
after they leave.
My edit: I am still thinking and wonder if Webmaster could give people another name and make it so the search system would be working.
I do a lot of archive reading and often I want to follow