The way to lower your ping, as I mentioned earlier, is to use an ethernet connection. Trust me, I gamed on wifi for years. Ping spikes are awful. I'm not even using a true wired connection at the moment - I have a mesh wifi network and my PC is connected via ethernet to the node on my desk. That communicates wirelessly to the master node connected to the modem downstairs. Sure it's not conventional, but my connection is so much more stable than before when just using wifi.
I just glanced at MSI's B460 offerings. Not one of them had an E-keyed M.2 slot aside from those already populated with integrated wfi (although if you take my advice about using a wired connection that can become a moot point). There were a couple with ALC1200, which, again, for your purposes of playing warzone, would be perfectly fine. But as
@oxrufiioxo mentioned earlier, PCIe 4.0 components add cost - that's part of why B550 boards were more expensive than their B450 counterparts. Expecting to find a B560 board in the $130-150 with all of the criteria you're deeming as must-have is going to be a tall order.
You literally mentioned in post #9 in the thread: "I'm cheap". I'll invite you to take a look at this
video from HWUB, specifically the final thoughts section that starts around 13 minutes. Yes the video primarily compares the gaming performance of the 3600 to the 5600X, but the quote at 13:22 makes a great point: "So if you happened to have upgraded from the Ryzen 5 3600 to the 5600X and aren't really seeing an improvement in games, which I have seen quite a few people report to us, this would be the reason why:
you are primarily GPU-bound when gaming. There will be some instances where the newer Zen 3 processor will help you out, but it's a lot like what we saw when comparing Zen 2 to the 9th and 10th gen core series:
yes, they are technically faster when you lower the resolution and use a really fast GPU, but under more typical, more realistic gaming conditions, it's hard to spot a difference and often you just can't". I'm extrapolating that to Intel's upcoming 11th gen CPUs. Sure, when paired with a really fast GPU where the CPU will be the bottleneck at 1080p, yeah, the 11400 will provide more frames than a 10400. But you're pairing one of these $150-$200 CPUs with a $400 GPU - you're going to be GPU bound, and likely won't notice a difference between the two. Add to that that PCIe 4.0 means nothing for gamers at this point in time, and the fact that you're going to have a much more stable gaming experience using a wired connection compared to a wireless one.
We've then eliminated the need for Wifi 6, 6E, or even rarer, the E-key M.2 slot you're obsessing over as well as PCIe 4.0. Which is exactly why I suggested opting for a 10th gen intel CPU and a Z490 board - it lets you bump your GPU (the component that impacts your gaming performance the most) up from a 3060Ti to a 3070. The Z490 Gaming Edge Wifi has 2.5G LAN (which you don't need unless you're paying for greater than gigabit internet), integrated Wifi 6 (pre-installed in an E-key M.2 slot

- not necessary if you're using a wired connection), and the ALC1200 codec.
My whole point is that you mention being cheap, which I interpreted to mean you want to get the best value for your money. The way to do that is to not pay for/focus on things that you don't need/won't make a difference in how your system performs, and allocate your budget towards the things that will (GPU).