That's not correct. Until 2008, 11x14 HP5 Plus was stock, but FP4 Plus wasn't, and had to be ordered through the annual "ULF" program. Starting in 2008, both emulsions became available only through the annual program. See page 3 of this document:
http://www.ilfordphoto.com/Webfiles/200866151713767.pdf
However, some distributors in some countries may order extra film during the annual program, or may have had HP5 Plus left over from when it was a stock item. In those cases, the 11x14 film would continue to be available to dealers unless/until the distributor runs out.

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