Is there a synonym for "centerfold" which doesn't also mean "scantily clad woman?"
Solution 1:
Centre spread is commonly used in publishing the the two-pages that belong to the same piece of paper and face each other.
Centre spread:
The two pages opposite each other in the middle of a newspaper or magazine, which usually deal only with one particular subject and include many pictures.
Example: Tomorrow's edition will include a centre spread on the Spanish royal family.
[Cambridge English Dictionary]
Or double-spread.
Double-spread:
An advertisement that covers two facing pages (as in a newspaper) — called also double-page spread.
[Merriam-Webster]
Solution 2:
Double truck: Double truck refers to a pair of facing pages, usually in a newspaper or magazine, with content that stretches over both pages.
In most newspapers and magazines, the booklet-like format is accomplished by folding large sheets of paper in half. This allows the pages to be opened like a book. Sometimes, usually only in magazines, the pages are stapled or stitched at the fold to hold the pages together.
[Wikipedia]
See Also
Double truck: a 2-page editorial or advertising layout (as in a newspaper) made up as a single unit
[Merriam-Webster]