If you check SampleRobot webpage you can see these few lines:

"SampleRobot 6 Pro and Multi-X even extend the huge sample format support with new exports like Yamaha MONTAGE and Synthstrom deluge.

The SampleRobot 6 line-up is planned to be released in June."

I now see a line that says that Samplerobot Montage will be available next month. ... so when a new month comes along, it'll always be correct.

To be more serious, the dates thrown out have little confidence given past schedule performance - so (more) patience is required.

Bummer but I can't complain much about something free that could easily succeed as a purchase.