It's a good sale, although it would be even better if they didn't neuter the already limited choice.
As a penny-pinching pauper I can sympathize with those who are tempted. I might even cave myself since John Wick Hex and Observation are so stupidly cheap, what would normally cost a combined €36.98 is a mere €14.08, a savings of about 62% for games that are not even out yet.
The way they're doing it is good too, consumers get a cheaper price, developers(publishers) still get the full amount, and Epic loses money. Also while I agree with the argument of them using it as PR fodder (although how effective that would be is unknown) I can't agree with the devaluation argument, since imho games are constantly devalued by time and by the release of other games in general, especially on PC where one can buy/play excellent games from 30 years ago and beyond.
It reminds me of Steam's best sale (opinion) in the past 5 years actually, which was this year's Lunar Sale. Developers obviously don't want to offer games too cheap, so Valve giving $5 out of their own cut resulted in consumers getting a better deal while devs didn't lose out. It also resulted in me grabbing smaller niche games I wouldn't have otherwise purchased unless they were cheaper (if ever): Spider: Rite of the Shrouded Moon, UmiharaKawase Shun, ZeroRanger, PUSS!, Brigand: Oaxaca, and Creepy Castle. As an aside, all of these are HIGHLY recommended. Except maybe Oaxaca, which while being incredibly interesting as a one-man Deus Ex project is also incredibly janky. So caution with that one.
All that said, however, it's also completely understandable if you don't want to support Epic's exclusive moneyhat bullshit by being a statistic they can use to their advantage when it comes to courting other developers/publishers.