I use openSUSE 42.2 64 bit Linux. I used kdesvn 1.7.0 from default openSUSE 42.2 reposotory. I tried to update programs (including kdesvn 2.0.0) from KDE:Extra repository (http://download.opensuse.org/repositories/KDE:/Extra/openSUSE_Leap_42.2/). After update, KDESVN 2.0.0 show empty list of bookmarks: no one imported/migrated from kdesvn 1.7.0. List of bookmarks was ~/.kde4/share/apps/kdesvn/bookmarks.xml But after manual copying into ~/.local/share/kdesvn/bookmarks.xml I get same bookmarks. I recommend to automatically migrate settings (at least bookmarks), if they exist in old configuration path, but new configuration is empty
Since 1.7 is using KDE4 and 2.0 is using Qt5/KF5 I don't see a chance to port the bookmarks. The bookmarks are handled by the KBookmark class and I don't find a way to trigger the migration of the bookmarks