No. But there are exceptional cases . . .
In general, the page numbers of the original book are irrelevant when making a reader's edition for PG; they are annoying and intrusive for anyone trying to read it, and if you did keep them, they would probably be removed by anyone converting it. Get rid of them!
But there are a few books where page numbers are appropriate. Non-fiction books that use page numbers as internal cross-references are the prime example; if, on page 204, the text reads
"Our studies of plants (see pp. 141-145) show that this is true."
and this kind of cross-reference is frequent throughout the text, then it is probably best to keep the page numbers, since it is otherwise very difficult to honor the author's intent.
In the more common case where cross-references exist, but are not frequent, and not essential to the text, you have several choices: leave the cross-references in, meaningless though the page numbers are, remove the cross-references, change the cross-references to something relevant (like "Start of Chapter 12" instead of "pages 141-145"), or, if you can make it work in context, insert references in the text for the cross-references to point to, like [Reference: Plants] and then reformat the cross-reference like "Our studies of plants (see [Reference: Plants]) show that this is true."
There are a few other cases, where the text you create is likely to be the subject of study or reference, in which it may also be desirable to retain page numbering.
When there are pages at the end of the book with notes referring to page numbers, the simplest answer is to change the page number references to chapter numbers, and add a quote from the page referred to if it's not already in the book's end-notes. That way, a reader can search for the phrase.