Yup. Just like they are with the Mac Mini right now.
Fact is, until Coffee Lake, there’s very, very little point in refreshing the Mac mini.
With coffee lake it might get 6 cores in it in the same TDP, a marginally better GPU, USB-C/Thunderbolt 3, etc.
Coffee Lake is the first intel CPU architecture worth bothering to upgrade to since Sandy Bridge, unless you’re either going for ultra high end HEDT workstation spec CPU (think socket 2011 i7/i9 with > 4 cores) or have been waiting for ultra low power (think core M) spec.
For anything in between (i.e., in the Mac world: macbook air, macbook pro, imac, mac mini), the upgrades since sandy bridge for CPU have been a resounding “meh”.
Sure, there have been other reasons to upgrade (better displays, better audio, new battery, new warranty, etc.) but since 2011 CPU advances have been totally snooze worthy for mainstream platforms.
edit:
Apple did actually bump to broadwell on the 13” macbook pros (i own one - and there was. marginal power efficiency improvement on those parts). on the 15”s they did not, and you know why? in some ways (GPU EDRAM if i recall), the broadwell parts were worse. pretty sure they had less EDRAM/level 4 cache than haswell. people cried their eyes out, but Apple made exactly the right call.