They still don't farm out the design and Synapse still don't do actual design or IP, for the most part they translate a design to production.
AMD do the design, they are fully capable of taking a design all the way through to finished product. Sometimes they'll outsource part of that process, sometimes they won't most likely.
One of the big deals with laying out a chip very specifically, and there were threads on comments from an ex AMD guy who said they were giving away 5-10% performance/power by doing it automatically. Is that there comes a stage where, when you are manually laying out small blocks of either hundreds or several thousand transistors, and the entire chip is 100million transistors, that is fine and doable. When it goes 200mil, still doable, 400mil... starting to be a lot of work, 800mil... wow 1.6billion, yowzer. 3.2billion uh oh.
Ultimately there comes a time where you need to go from a manual to a automatic process because anything else is simply not viable. 10% performance is great, but if you go from 10 guys taking a year to 200 guys, your costs just went up exponentially, and effectively these would continue to rise with every doubling of transistor count.
This is where HDL libraries come in, automatic process isn't perfected, it takes time, hence the high density libraries for the tools that carry out the work. They have stated that a Piledriver(I believe it was) would have been 30% smaller and less power(if that is both reduced by 30%, or pick and chose, 30% smaller same power, 30% less power same size, or go 15/15, it was unclear, either way that is either great or epic). I tried to look it up, it's perfectly possible that Synapse helped them with the libraries, but I get the impression that part is still done by AMD as I can't see any references to the HDL and it being outsourced. Though to an engineer, going from 10-50 engineers doing it manually to letting a computer doing it automatically would basically be the same thing if they get fired.
It's likely Synapse employs a bunch of ex AMD, ex Intel, ex IBM, ex TSMC, ex UMC and ex Apple engineers to do the work anyway. So it could literally be the same group of people doing the same work, just under a different company name and no I wouldn't be disappointed.
There is a reason AMD spun off the foundry, why Intel are now taking on more foundry customers than ever before, why IBM have sold off their foundries, why Semi Chartered sold their foundries(taiwanese or sinagpore group of smaller fabs that GloFo bought shortly after being formed). A single company, even Intel, can't continue to do everything themselves.
Because taping out is pretty much process specific(many parts are, the design rules etc) then one company doing all the work on 28nm at TSMC and everyone using them makes much more sense than 50 companies making chips to all do the same work. You would have taping out specialised workers... who tape out say 3 products a year... rather than hire those specialised workers for the 3 months of a year that you need.
I forget the company name, something like Applied Materials, who make all of TSMC's fab equipment, and they make all of Intel's equipment. Share the development costs or double the work and make everything more expensive. Like object oriented programming, use the best, most efficient solution to everything. Architecture, do yourself, anything else, if someone else can do it quicker, or better, or both, why would you throw away money doing it yourself?
This is more of an issue since the spin off of GloFo, GloFo needed to become more industry standard, and as such more people specialise in their processes and gain experience of it. They taped out 33 products, AMD didn't, they have more experience taping out products than AMD at 28nm because they do it more often. To not utilise that experience is simply daft.
I find it odd that anyone thinks subcontracting out work, when talking about the scale of billion dollar companies.... is disappointing. 10 guys employed by AMD do a job, or 10 guys who work for Synapse, who are employed by AMD, do the job.... I see literally no difference at all.
Look at any huge company, call every department a different name, no different. When you get to huge scale companies, smart decisions keep you afloat, bad decisions see you go bankrupt. AMD are making smart decisions now, part of that is outsourcing where required.