Yes, the purity of AWs elongata is a controversial subject. I personally believe that he does distribute pure H. elongata, however the clone is not very good. I've talked with somebody who works for Andreas and is one of the few people to have grown the AW H. elongata to make mature pitchers, who believes the clone is pure. I know another person who works for AW who is not entirely sure about elongata but does not outlaw the possibility of it being true, just that it's not a great clone. To add to the confusion, AW has sold two elongata clones over the years, one which is not very good and the other one which is much better.
And surprisingly it's not a typo! I actually know a number of people who can say that 15-20 years is a perfectly accurate estimate of time for elongata to make mature pitchers. Mine has been making immatures for 2.5 years or so and I'm not holding my breath
. I have a 15 year old H. ionasi that took 10 years to make its first mature pitcher from AW. Ionasi and elongata both are kind of notorious in the heli community for taking ages to make their first mature pitchers.