I think the BIOS version indicated on the site seems to suggest it's an older BIOS, so it should work out of the box.
I would guess the thinking behind what you were told is because APUs are seen more of an FM2(+) socket rather than AM4. AM4 is associated with Ryzen. Plus the Ryzen/Vega APU hasn't been released yet.
The current APUs still use the old technology. But, depending on your plans, will allow you a better upgrade path: Ryzen/Vega APUs when they are available, or a Ryzen CPU and discrete graphics card.