According to the Jagex live stream on March 26, 2019, ioS and the Android versions will be available on launch.
"The intention is to have both iOS and Android versions on launch, so iOS will happen. Can't give a date on iOS beta but it's in development and is coming along really well."
Jagex gave their reason on giving better experience for a lot of incoming new players:
"New player experience
We're doing a lot for the rest of this year.
You'll see a lot of changes throughout the year on the first user experience, especially leading up to full commercial launch of mobile.
Post-tutorial is really important to look at, so we'll be focussing on that. If that goes well we may look back at the tutorial.
What if mobile doesn't bring in as many players as hoped? We're pretty confident because if you look at the launch of OSRS mobile and how well that's done, we've got really good data on how that's performed; and all the indicators are that we will see a good number of new players incoming. We're hoping with RS it'll do even better [than OSRS]."
