I have also sent the assets a long time before to Darkhorse. Will the new assets come my way automatically or do I need to do anything at the moment?
You should already have the new coin then. Keep in mind it's now an actually currency, not an asset. So it won't be displayed in the same way.
This is the new currency, XOS:
https://nxtportal.org/currencies/17415019753777810897// Mac