I'm a bit sad as to the changes as I cut my teeth on Mac OS X Server as a system administrator. Started with ASIP, but OS X Server was when I really got going. It was good and did what we asked of it before the beginning of it's demise in Lion.
That being said I don't believe you were wanting nostalgia here so we'll move on to practical...the most recent planned changes for the product will cut almost all services available in it to the point that it may as well be renamed "Apple Profile Manager." That being said, our shop uses Jamf Pro and not Profile Manager. Even Apple will tell you that Profile Manager was only intended as a reference product and for larger shops they recommend a true MDM platform such as Jamf Pro.
I can't fault Apple too much for not wanting to be in the server/infrastructure space as MS-based products are entrenched worldwide. I don't believe that will change and even if it were to start to, it would take years and years. As such, I believe that what Apple needs to do is keep Profile Manager as a "reference platform" for MDM providers to have a spec to build toward, but focus on making their enterprise tools work well with Microsoft shop infrastructure. When I say that, I specifically am referring to Enterprise Connect. From what I read and see about the product, it is good and gives me the benefits of AD without the bind. This needs to be a downloadable App Store app product that is well documented for anyone to use at a minimum and ideally be included in macOS at the ideal.
In short, I have no choice but to adapt as Apple has effectively pulled out of the server/infrastructure space with the demise of OS X Server. I just hope that they give me a stronger set of tools to work better with MDM products such as Jamf and better with existing Microsoft infrastructures for directory, file shares, etc.
My two cents on the subject. RIP Mac OS X Server, I began my career on you, but we seem to be at the end of an era.
I saw this coming when Apple killed off the Xserve, and then released the Server app with Lion. Lion Server was an interesting hybrid of the server app and the old OS X Server. Releasing the server app pretty much made Apple's server a consumer product. I kept using it for small offices though. It seemed to work well. I think Microsoft's desktop and consumer products are crap, but their enterprise products are really great (for the most part). I just learned how to use Hyper-V, and I have been really impressed so far. My experience before this was with VMware. My focust at my company is to help our Mac using clients succeed with Apple technology. To that end, I don't care what's running things on the back end as long as the technologies we deploy work great. We're about to move our Jamf Pro server to Linux, and I will be creating more Jamf Pro servers in Hyper-V soon. I am saddened to see Apple's server go away, but I'm not surprised by it. Snow Leopard server was, in my opinion, the best Apple server of them all. I really wish Apple would release a set of tools that could be installed on top of Linux so that we could give Mac and iOS users Apple specific features, but that is really not in their strategy. Apple seems to want to integrate instead of dominate. That's fine with me as long as they maintain great quality.
It was inevitable that Apple was slowly killing it, but it is still sad. Their WIKI was really well done in my opinion. I wish they did this last year as I just bought a super awesome MacMini from 2014 last year as my other one was fading fast. If I was going to setup a Linux box anyway, I could have bought modern technology for half the price.
Still, I will miss the Wiki, easy email and websites. I could care less about Profile Manager and most of the features that are "saved".
@StoneMagnet The reason for the switch is because the company I work for now is heavily into Hyper-V. I love VMware, but that's not what we use. I do have some servers hosted that are running in VMware, but I don't have access to VMware itself, only my servers. I have found that Hyper-V is actually easier to use when setting up a new VM. My only real concern about it is that it is running on top of an OS that needs a lot more memory to operate than the underlying OS in VMware ESXi needs.