This is the kind of topic I hate to make. As a fan, this game does a good job at fan service, (Not on the level of Alien: Isolation) but I do not think Predator Hunting Grounds will do well financially.
First is the lack of content. Spending $40 dollars on a multiplayer-only game is a big risk especially from an indie developer. The success of the game is dependent on people buying it and people have to feel confident that others will jump to buy. There are likely to be only 3 maps and one game mode that is limited to 5 players max. Most of the weapons are locked behind progression levels which stink of Star Wars Battlefront (not a good smell). This progression is just a sad replacement for compelling gameplay. It doesn't help that the Predator player is severely gimped without these weapons. Put this together with a lack of different gameplay modes and a small selection of maps and weapons and the gameplay is going to get stale faster than you can unlock new toys.
This game needs something more! Back in AVP2, they had a hunt multiplayer mod which basically offers the same gameplay for the predator, with more maps, more weapons, and more players. And that was only a small subsection of multiplayer for that game, like 2% of the gameplay on offer. There could have been predator vs predator modes, you could have made humans teams larger than 4 or have dedicated evac mod. Or some kind of single-player skirmish or story mode.
Second is small, but it is the possibility of microtransactions. The loot boxes (or whatever this game is calling them) are unethical. I am also pretty sure it is illegal gambling in some countries now. I know it is cosmetic only, but the behavior just shows that they are trying to milk players and given that it takes up a whole option on the main menu hints that development focus on this game was misplaced. I would rather pay an extra $10 for a game with more content than one with microtransactions. Now it is small and might only be cosmetic stuff but it will leave a bad taste in people's mouths seeing it on the main menu of this game.
The third is the matchmaking. Currently, you have people pick whether they want to be a predator or human, and often most of the predator player players get matched into a game as a human. (I got matched into a game as a human with no predator player I choose the predator matchmaker!) It takes forever (right now) to find a match and the matches are over faster than the waiting in the lobby. As soon as the predator player drops or leaves the game ends, which shouldn't happen after he is killed.
A better system would have been to match people in lobbies. The predator player is then chosen at random from that lobby and the player can refuse if they want to play as a human. If the predator player quits in the middle of a game someone else is chosen to assume the role. And the lobby should stick together so the next match can be started right after the last one.
Fourthly, this only applies to PC, but it is Epic Games Store. It is not going to be better than steam anytime soon, and the platform is currently running at a loss. You miss probably 80% of the PC players by making it an Epic Games exclusive. Only fans are going to look to buy it, causal players won't buy games unless it is put onto their radar, which Steam does well with seasonal sales, free weekends, and the daily promotions it does. If this game does come to steam I fear it will be too late at the game will have died by that point.
Finally, it is the free demo weekend itself. Honestly having the free demo is great, it never happens these days before the release of a game. But it never happens for a reason. Most players (the causal ones) don't put more than 10 hours into the average game. There is a significant minority of players who don't even play every game they buy. I feel like the demo can work against itself by either exposing problems with the game or by satiating the player's interest in the game.
None of the above have anything to with the gameplay mechanics or the graphics. And if you are a fan it really shouldn't influence your decision in buying this game. This game has so much potential but I don't think this game will be alive this time next year. Rant over.