There is an opinion that Thielert will eventually vanish as a standalone company.
Their existing business is probably highly dependent on having a significant number of DA40TDi and DA42 owners held firmly by their goolies, because the cost of changing to the Austro engine is so high. But, over time, many of them will either scrap the aircraft, or change the engines.
Also, in the opinion of owners I know, this is not a "long life" aircraft and suffers continuous degradation through corrosion of the many metal fittings. It is a cheaply made aircraft. This is not an issue in the short term but makes it difficult to take a long view.
I know of some people who have tried to sell their DA42s and found no takers at anything below a totally silly-low price.
It's a nice aircraft but there are significant risk factors with it.