For sms sent for JB, the name is generated in the format of "Content-Generated-Message-08015ffd-5a62-4490-b941-742af051ccae" which we want to change (we are ready to do it manually) to have more meaningful data in the reports. Is it possible?
With the Jan. 2020 release this will be possible,
When you use MobileConnect with Journey Builder, you have full control of your SMS message name in Journey Builder. SMS messages sent through Journey Builder now use the Activity Name as the Message Name in all reports and data extracts. The Activity Name gets populated with the content name, but you can edit it in the activity.
I'm facing the same issue (as it also breaks campaign association) and right now this does not seem to be possible - you simply are not able to change the name of an active text message.
The only workaround in place that you can have right now is to have a secondary data extension where you log the original name of the text message and the corresponding "Content-Generated-Message" - combine that to get your report.
Keep in mind the fact you would need to add records to this table each time you activate a new version of your journey - each time new content-generated-messages will be created in Mobile Connect.
To add salt to the wound, there is another part of the system that would solve this - in Journey Builder when you configure your SMS activities you can see the 'Advanced Options' section which shows you something described as MobileConnect Reporting Name. If your SMS had the name 'Your SMS Subject' it says it would generate a name by extending that sms with a random string (for example "Your SMS Subject-d10bf875b5ba4daf896afed79a5a6f4b"), but right now names are not created this way.