That is an absolute lie. Springfield has, on numerous occasions, said that all of their XD lines are rated for +P ammo except the subcompact models which they suggested not to use +P ammo due to the short cycle of the shorter slide length. Almost all modern handguns are rated for +P.
I have fired several boxes of +P Federal HST rounds through my XD45acp Service model without a hiccup.
I have read many an email posted on this exact subject and every one stated that XD's are safe for +P.
Here is one email I captured:
"Due to the fact that our entire line of XD pistols features fully supported and ramped barrels, using +P and +P+ ammunition will not damage your gun. However, we do recommend that you make sure the ammunition is American made and is in new condition. Due to the increased power of +P and +P+ ammunition, the cycling of your XD may be affected by this different ammunition. If you are planning to use +P or +P+, we recommend that you fire it extensively at the range before relying on it for concealed carry or self defense. It is important to ensure that it will run reliably in your XD. Although +P or +P+ ammunition will not damage your XD, a steady diet of this higher power ammo may decrease the service life of the barrel and/or firearm."
John D Moe