I was skeptical too, but a couple of community members have talked to the manufacturers and gotten the repeater verification.
However, if you connect through a Hue bridge, they probably won’t repeat your ZHA device messages because they think the bridge is their controller, not the hub.
updated to add
Osram marketing materials do say they’re using the ZHA standard:
connects to LIGHTIFY devices (up to 50 per each Gateway) via the ZigBee Home Automation standard. Initial products include a true A19 Tunable White 60W replacement LED bulb which delivers over 800 lumens, unlike other 60W
See also the following discussion, which says that Osram confirmed that the lightify bulbs sold in the US are ZHA profile while the ones sold in Europe are ZLL profile, and they can send a firmware update to shift from one to the other.
This is just Internet discussion, so would need to be officially confirmed, but it’s from the everyhue forum with generally reliable sources:
http://www.everyhue.com/vanilla/discussion/1766/third-party-hardware