FIRST Tom's hardware needs to go back to their 10900k review and correct where they said "they're similar in price" when comparing the 3900x and the 10900k. The 3900x is 25% cheaper and is nowhere near being in "the same area" with respect to price as the original review suggested multiple times. So please change that so consumers have an honest appraisal.
"Thanks Intel"....?? Just an FYI, but the 3900x was as low as $417 Two Months AGO, so it's both incorrect and disingenuous to imply that the 3900x was at MSRP the day before the 10th gen Intel CPUs were released, which isn't the case at all. Yes, competition leads to lower prices, but based on the fact that the 3900x was this cheap months ago, I guarantee the PRIMARY and PREDOMINANT reason the 3900x is discounted is so AMD can clear stock before Ryzen 4000/Zen3 is released (with recent leaks suggesting that they could be released as early as August/September).
At $500 the 3900x is still stiff competition for the 10900k, so based on the facts I've already stated, it's more likely a result of seeking to reduce stock.