Thank you for watching, voting, and commenting on this issue.
We use this data as well as many other inputs to feed into our prioritisation process. Being able to add labels to the cards in the Backlog view will be something that will be available in next-gen, although it is not something that we will be focusing on in the next year. We want to share this with you to ensure you can plan out your use of projects within Jira Software effectively.
In the short term we recommend teams use classic projects if this is an absolute must for you. We apologise for the inconvenience this may cause you.
Please continue to vote and in particular please continue to add comments on how your team would find value when having labels on the cards in the Backlog. This contextual information of what you are doing and why you are doing is invaluable for us in providing you with a product that will grow with your needs.