Whether or not the inverters or any other equipment utilizes a neutral is an irrelevant detail that is a distraction from the original question. You need an effective ground-fault current path at the disconnect, and to do this you need an adequately sized wire bonding the disconnect enclosure to the service neutral. One way to do this is, as advocated above by shortcircuit2, is to call the the new PV disconnect a service disconnect and to then comply with 250.24(C) and other sections that require bringing a neutral to the disconnect and installing a main bonding jumper. Another way is to bring a supply-side bonding jumper sized to 250.102. It is not really valid to use table 250.122 for sizing since there is no OCPD ahead of the disconnect, hence I strongly suggest using 250.102, especially the minimum size. However, as long as the wire is adequately sized and ultimately connects to the service neutral, it really does not matter if it is white or green. The code ultimately only requires one wire, not two. (This is leaving aside grounding electrode conductor stuff, which depends on other details not essential to the main question).
In the past I've posted a list of code sections that can be used to argue 'for' and 'against' considering a supply-side disconnect to be a service disconnect. (But I don't have that list on the device I'm typing this on and I'm having trouble finding it with searches.) It is notable, as shortcircuit mentioned above, that the 2020 NEC changes the definition of a service. Thus the strongest argument that it is 'not a service disconnect' is no longer supported by the code. On the other hand, there was proposed language for the 2020 NEC that would have told us exactly how we could ground the disconnect in the new 705.11, but it got deleted from the final version. I don't have the inside scoop on how and why it got left out, but I do know there were negative comments filed against the first draft. I hypothesize that the CMP couldn't come to enough of an agreement on the matter, so they just punted the issue as they always have in the past. So really, not all that much has changed. It's still up to the AHJ.
hhisting as a contractor to the AHJ I think you are free to make your own recommendation as to whether to consider the disconnect a service disconnect, if they do not already have a clear policy in place.