OK, but how do you attribute a coherent strategy to Apple not updating the Mac Mini for four years, from late 2014 to late 2018? That seems more like a lack of coherent strategy to me—like maybe they couldn't decide whether they were going to drop it or not. And while of course other considerations can intervene and cause delays, I don't see how one could seriously say that external factors (e.g., delays in Intel's roadmap) prevented Apple from updating it for four whole years.I think it is actually part of a strategy. Obviously some models are less profitable than others and may see longer release intervals. There are also external circumstances that historically has affected the release cadence, i.e. Intels failure to deliver on their roadmap.
Having worked a directly or indirectly in product development my whole career I would not believe Apple acts without a strategy. But sometimes there are other considerations which "messes" with your strategy. The current transition roadmap seems fairly clear at this point but Apple has not reached a stable release cadence with the new chips yet.