Channel specific SKUs is common already, but would it be legal to use the same trick for same-channel seasonal sales? I'm not aware of it being done, but maybe it is and I just haven't noticed.
For example, sell product all year round as item sku-0001 for $100, while also listing an identical product as item sku-0001b which costs $150 but is not promoted at all. Then the day before black friday, stop selling item sku-0001, and promote item sku-0001b for $105 with a flashing "30% off!!" sign?
If you're a third party trying this on Amazon then it has downsides such as lack of reviews, poor ranking etc. on sku-0001b that most of the year nobody is buying. But if you're a retailer with your own online shop, then you just say that the reviews are for this family of products and display the sku-0001 reviews on the sku-0001b page while promoting sku-0001b heavily during the black friday campaign...
And then the day after the sale ends, item sku-0001 magically reappears for its usual price of $100 ($5 cheaper than sku-0001b's sale price, but no flashing banner to promote the fact) and sku-0001b spends the next months to a year not being bought or promoted again.