Just reiterating what Zeke stated already pretty much.
I prefer to think in terms of intensity. To me, a tempo run is at most a moderate intensity run. It’s not easy but it’s not a gut wrenching experience. Save those gut wrenching workouts for the final 12 weeks but go ahead and do an occasional tempo run, even a fartlek run as long as you don’t make it too hard, before. In fact, as Zeke referenced a while back when mentioning Lydiard, strides are technically anaerobic but are great to do in any phase of training. To me, this still falls into the moderate intensity thing. Strides are not all that hard. They are quite fast but they don’t last long enough to be really hard.