JK, while I rarely think I get exactly what you are driving at.... I think I would disagree with a notion that new grow-in courses are necessarily hurt by opinionators who experience them before optimally grown-in, as opposed to any course fully grown-in or not that may suffer from closed minded opinionated members or non-members expressing their reaction to playing courses and the conditions they find them on their one preview.
As long as one opines, and makes it clear that they formed an opinion when the course was not in optimal conditions, but can speak to the bones of what is there, then I think it is part of the risk one takes to invite anyone to have a preview, because you can't prevent them from writing or talking and expressing their opinions. If you have a course that simply isn't ready for review or opinion, don't let anyone near it!
But, that is not how this new era of golf course architecture and development works. TD is IMHO, the master at teasing out there a preview. I remember very well the run-up to Pac Dunes and BallyNeal, and the preview excursions many contributors here made to the discussion of those courses, when they were no where near fully grown in. But, as the saying goes; 'it is what it is'. If it has negatives, aside from maintenance grow-in, and if the opinionator makes it clear that negatives are described, APART FROM CONDITIONS OF GROW-IN, then the developer and archie are putting themselves up for the critique, and the chips fall as they may.
Developers and archies use us, as much as we may abuse them with a negative comment, after a so-called 'preview' round, if that invite was extended, and no gentleman's or even written agreement is made for "no comment". But, 'no comment' is exactly what the developers and archies don't seem to want. They embrace the buzz. It is a two edged sword, IMHO. There is also the consideration of ethics. If one is invited, and is not asked specifically not to comment, or encouraged to comment for the buzz factor, one still needs to apply ethics and disclose things like the turf was no where near grown in, no sand in Bs, and rough still not grubbed out, etc.
Closed minded is a negative and most of us know that when we see it in opinions. But, opinionated and informed, with fair disclosures is why we come here to discuss... isn't it?