YouTube's mobile live streaming is reaching more users as it appears that some channels that have under the 10,000 subscriber mark have been able to access the functionality. According to one user on Twitter, who seems to have been one of those to discover this capability, upon opening up the YouTube app a new live streaming message appeared at the bottom of the home screen tab on the floating action button that emphasized Live Streaming was new and now available. The channel on YouTube who has pointed this out is YTS, who mentions in the Twitter comments that they personally have close to 3,000 subscribers so they're nowhere near the mark of where the limitation used to be. It's also worth noting that anyone is capable of going live on desktop regardless of subscriber numbers, so the limitation is something that's only applied to mobile, which means that YouTube may be getting ready to push this out to everyone.
There is no indication that YouTube has mentioned this change yet, but it does seem to be showing up for other users incrementally so it may have been a feature that was already available and Google may just have to flip a switch to enable it. With that said there are sure to be some users who don't have the feature showing up in their apps yet, and it's also entirely possible that it may be part of an app update.
If Google is starting to roll this out to everyone via mobile devices it isn't mentioned how many subscribers you may need to gain access, or if Google is simply lifting any limits previously associated with subscriber numbers that users needed to hit before they could use the feature on their smartphones. It's stated that channels as low as 2,700 subscribers have verified the feature to be available to them so it seems like there may still be some minimum number of subscribers that has to be met, but with it being lower than before it could signify that Google is preparing to open up the feature to everyone in the near future, though how long it would be before any channel has access is unclear.