Oh I think it's far worse than that. Because you have to ask yourself: what is the fastest way to gain karma on reddit? And the answer is not by sharing an opinion.
The top up voted posts each month are likely going to be media of animals, some nsfw content, and news articles. All of which are posted by bots nonstop.
Because the truth is that karma already is money. People pay money for accounts with high karma. And then turn them into bot accounts or advertising accounts. So now those people will just be able to double dip.
In short: it's likely that reddit will just become a larger bot network if they do this. Karma systems don't lead to better posts. In fact, I'd almost prefer to keep the karma system on lemmy/kbin and just have it private.
Meanwhile subs like ComedyHeaven literally approve like one post a month for a whole year 💀