Look around, it's actively happening. Many jurisdictions have instituted deadlines, past which ICE vehicles won't be allowed. Where I live, I won't be able to register an ICE car manufactured after 2030.
Instead of looking I can read the data. Most western countries are selling between 2-20% of EVs. I think it is very reasonable to assume these "deadlines" will be extended.
But even in regards to this topic the small percentage of sales Germany manufactures might have missed out on EVs could easily be overcome with advertising or other external factors.
Germany is already at 18% and rising rapidly, there doesn't seem to be a problem selling EV cars even in larger countries. Norway is 80% but they have oil money, but even Sweden is at 32% and they are sparsely populated and not richer than Germany.
So I see no reason why banning non EV by 2030 in some countries is impossible, Germany and many similar countries are ahead of the curve needed to get there.
There is no evidence to suggest the rate will increase but evidence that it will decrease. The demand for non-EV worldwide is growing rapidly and if Germany doesn't want to compete on this market there will be other countries standing in line.