Hey all, this is my first post here. I do Buchla 100 Series recreations as Catalyst Audio. I thought I might be able to add something constructive to this dialogue.
So at this point I don’t know if there is any clear cut answer.
I can say that I think very highly of all of the people who (I know of) that currently work at Buchla USA.
I have known Eric Fox for a number of years and he has always been honest and ethical.
My understanding is that at this point most or all of the people who were involved with BEMI (and the lawsuit against Don) are gone, and if there are any left they are there as investors only with no say in day to day operations.
Buchla USA is cool with the modules that I am doing, I have talked with Eric, Joel (Buchla’s main engineer), and Mark Doty at superbooth and NAMM. We have talked about potentially working together on projects in the future. 
The 200 series stuff (in Buchla format) is a bit more of a grey area.
Buchla USA isn’t particularly happy about it, however I know that Eric is sympathetic to the fact that there really aren’t any other options currently if you want a 200 series system. I have heard rumors that there may be “official” 200 series modules at some point, but I don’t know more than that.
As far as ethical concerns about it - I think that is something that each user has to decide for themselves. There is (to my knowledge) nothing particularly shady happening behind the scenes. Don Buchla likely wouldn’t have wanted anyone doing these modules, simply because he didn’t see the point in rehashing old designs. (But that likely applies to even the “new” Easel produced by Buchla USA)
As far as his family and legacy goes, (again I don’t have first hand knowledge) my understanding is that both Buchla USA and the 200 series “clone” people have been in contact with Ezra Buchla, as well as some of the other more explicit “anti-clone” old school Buchla users and would be happy to have them involved, but have so far not had much interest. Maybe this will change in the future, maybe some stuff that happened in the past is still too fresh, or maybe people have just moved on.
[Edit - Ezra B contacted me in regards to this section of my post, and made it clear that he has very good reasons to not be involved with Buchla USA. If anyone has interest in understanding this better I would suggest that you contact him as he will be able to give you a much more knowledgeable response than I can.]
On a more personal note, when deciding to do the 100 Series modules, I debated about the ethics behind it for a long time and eventually decided that:
A. they wouldn’t cause any distress to Don Buchla (he had already passed on.)
B. they would not interfere with anyone else’s ability to make a living (no one else was doing 100 series at the time)
C. they had the potential to make people happy.
I talked with a number of people who’s ethics and thought process I respect, and no one I talked to could really come up with a good reason not to do them.
Of course this decision was based on my own set of values, and other people might well have come to a different conclusion.
Anyway, thats my best insight into the issue. Please don’t take any of what I have said as “big T truth” because a lot of it is just what I have heard from being around this “stuff” for a while.