Formula 1's governing body revealed more detail into the upcoming changes, which aim to produce lighter and smaller cars as well as moving towards a more sustainable future, earlier in June.
Amongst other changes, DRS will be removed for the first time since its inception in 2011, with a push-to-pass style electrical energy boost being introduced instead.
Engines will see an almost 300% increase in electrical power, as well as being powered by 100% sustainable fuel.
However, there have been some concerns raised about the plans.
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Though the FIA is keen to beckon in a more sustainable era with better racing, teams, pundits, and drivers have been quick to point out potential flaws.
Sky Sports pundit and former F1 driver Martin Brundle noted a safety issue, writing: "I'd personally be a concerned about significantly moveable front and rear wings should they not return to the correct position for a very high-speed corner due to debris, damage, or malfunction."
Horner, though, backed the FIA to get the new regulations right, suggesting that the concerns he voiced in 2023 had been eased.
The Red Bull boss was asked about FIA single-seat director Nikolas Tombazis' comments in response to critics that there was the potential to change the engine balance in order to lift performance.
"There's always one that doesn't want to change anything," he told media at the Canadian Grand Prix. "Look, that's down to the FIA. It's never too late - they have all the knowledge and all the simulations.
"Absolutely, the one thing we've got is time. And I think the FIA have been very open in their listening, they've taken the feedback... but I'm not too worried about it."
Horner's Red Bull aced the latest set of new regulations in 2022, which has led to an era of dominance for three-time world champion Max Verstappen.
"I think you've got to look at what's best for Formula 1 at the end of the day, and what will produce the best racing, so trust in them [the FIA] and FOM [Formula One Management] to make the right calls," Horner added.
"But, whether that's required or not, I think they've got all the knowledge to know."