A wide variety of mono-Green decks in Commander were happy to see this guy reprinted. These include decks led by Seton, Krosan Protector, Azusa, Lost But Seeking, and Ezuri, Renegade Leader. Basically, any mono-Green deck that's focused on creating a huge army of creatures will want Regal Force in its arsenal. Seven mana to cast is a lot, but he's proven his worth time and time again over the years.
While this Eternal Masters printing will tank his price, which was based on his very low supply, it's likely he'll rebound over time considering just how many decks can use his ability. Card draw is always going to be good, especially in Green.