When you make changes to your bot, an orange banner will appear at the top of the page asking you if you want to push changes live.
This button will push any edits or messages you've made to your bot live so they are accessible to your bot users. You can push your changes live as your edit your messages, or after you've made bulk edits - it's totally up to you.
Please make sure that you have pushed changes live for any broadcasts you have scheduled or any bot flows that are being tested or launched.
Maintaining development and production versions of a bot
Consider a bot as the whole thing, but within the bot, you will have development / staging / production version of message flows. So you can still push changes live to a whole bot, but keep certain flows hidden and undiscoverable. People often use categories to denote which version of the message flow it is. You can also change the message title to "{Message title} - DEV".
These message flows should be hidden behind keywords, or only tested by broadcasts to test segments. Once you're happy with your new message flows, you can hook them up in place to go live by connecting them to a live button or keyword, or by broadcasting the message out to users.