They did, but recently GloFlo announced that they're stopping R&D on newer nodes and are switching purely to sustaining engineering.

Everyone working on R&D either got laid off, or moved to sustaining engineering on existing nodes. AMD is doing 7nm on TSMC. That's about as shut down as foundries get since the capital investment is all up front.

AMD's strategy of using multiple Zen 2 dies (7nm) tied together by a 14nm I/O die (since I/O doesn't scale down quite as well) is a really interesting strategy to improve yields using smaller dies (rather than making huge, low yield chips like the competition) & reduce mask/production cost. One 7nm Zen 2 mask can be used to produce CPU cores for a multitude of SKUs, optimizing for different markets using (cheaply customized) I/O interconnects made on 14nm.

This allows for AMD to keep much less silicon on hand for stocking the myriad of SKUs, as the only bottleneck for ramping up production of a SKU is producing those I/O interconnects on 14nm, which is a well understood process.

AMD isn't shipping any new GloFlo processors, and GloFlo either laid off or shifted their all of their R&D to sustaining.

That's as close to shutting down as foundries get.