I realized that normal text (technic text of Sibelius) was not imported from the xml file into Dorico. Lyrics were imported very nice and they look much better than in Sibelius (in fact something that very often worried me in Sibelius).
Text import worked with MuseScore, so it is possible. Thus my question:
Are there plans to improve the xml import in (the near) future?
XML import is being improved : we already know that there will be a filtering feature in the next update, where we will be able to choose which informations will be imported.
You have to know that XML is not a perfect format, it is really evolving and, as such, no software really exports XML the same way (or right way !), making it rather complicated for other software to “interpret” everything perfectly. Dorico does quite well in importing XML files, if I understand well what is being written here since november…
Thanks for he reply. So I can have hope for the coming update. 
In the next update barlines, repeat endings, and chord symbols will be imported from MusicXML, but there are no changes to the import of text.