The article doesn't mention a reduction in the airbus fleet of 10-20 percent. It says the short-haul fleet will be reduced by 10-20 percent - this will mainly be due to the removal of the Dash8.
Yes, you could be correct, - although I read the article as the Dash8 fleet. counted separately, being owned by LGW (Luftfahrtgesellschaft Walter), bought by Lufthansa in 2017 and subsequently sold on to Zeitfracht Group last year with a long term leasing agreement to operate newer E190's (replacing Dash8) for Eurowings