Berger had first revealed that the DTM was considering a name change to reflect its bid to become a more international championship at last year's Brands Hatch round, and Motorsport.com understands that the series has been mulling over options during 2019.
When asked by Motorsport.com if the DTM was continuing to push for a name change, Berger said the series is "working on it", before confirming 2021 as a likely introduction point.
The DTM's bid to become more international has led to comparisons with the short-lived International Touring Car Championship of the 1990s (pictured below).
A collapse in manufacturer support, partly a result of rising costs, led to the ITC's demise after the 1996 season, and Berger is hesitant to use the joint Class One regulations with SUPER GT to launch a 'world' championship.
"The next step is to stabilise everything in Europe, improve step-by-step. Here [at Brands Hatch] we have more people than last year, great, it’s a good step," said Berger. "But it's possible to do another step next year.
"You need to have passion, work hard. In certain countries in Europe, this [Britain] is one of our big names. It is important for the manufacturers as it gives the possibility to use the development costs [of Class One] in different continents and that is going to be better.
"It all takes time, you need to pace it. I think everything is moving in a good way."
Giancarlo Fisichella, Alfa Romeo 155 V6 Ti
Prodded further over the ITC comparison, Berger added: "With world championships - some are good - but it’s connected to high logistic costs, and most of these projects are killed by it.
"If you look at Formula 1 and MotoGP, they have such a big business that the logistics are done in a good way. But for us, to do a race in Japan [in November at Fuji], we need to fly a jumbo there and it gets complicated, difficult and expensive.
"I wouldn’t run blind in a way [where] we go ‘OK, we do a world championship’. Let's focus on Europe and getting stronger in Europe, especially in Britain."
Berger added that he was keen to have a French race on the DTM calendar in the future and said the series may move away from Misano to another Italian circuit for the 2020 season.
The abandonment of the night race format trialled in 2018 and MotoGP star Andrea Dovizioso's guest drive failed to improve attendance at Misano this year.
Andrea Dovizioso, Audi Sport Team WRT, Audi RS 5 DTM