Hi Vipul,
I am not sure about 5.0.24 version expiry as there is no news I could find regarding this.
Blue Prism 7.0 offers few newly added features and few integration support features than the former,you can always check out for the latest product releases on Blue Prism Product release page.
Yes,there are few challenges when migrating automation latest version that can be only explained via experiences ,for us there were few spy issues ,I hope experienced people could shed some more light on this topic and suggest to go for few POCs in your organisation to observe how your environments are reacting.
You can also check out this page for upgrading related queries -
https://bpdocs.blueprism.com/bp-7-1/en-us/release-notes/upgrade-notices.htmI hope I could help you in some way.
Thank you