Thanks to all for replying!
In my understanding it is common practice to give business partners a concrete timeline, when functions are to be discontinued. Partners need this to plan their own IT projects which are needed to replace the lost function. It is, for example not cost efficient for us, to search for a replacement within 6 months, when Evernote already decided to keep the Legacy version for a year, but did not communicate this.
The CEO, Ian Small should explain why Evernote has decided not to do this in case of the Legacy version. I already send him a letter and tried to contact him via Twitter.
Best Regards, Rainer Winkler