So, Stealth is suspected to be an issue with the launch mechanism, which is difficult to fix since Intamin discontinued it and stopped support on existing accelerators. It is a very difficult issue for them to repair without the help of Intamin so Stealth could be a lot longer closure. Keep in mind I got this from a friend who knows maintenance staff.
With Rita, the issues is with the catch car rather than the main launch system. Rita is expected to be open within the next week or two.
To summarise, Rita most likely 1-2 weeks closure. Stealth I’d imagine will be later in the month, so opening for the latter I’d estimate to be, like 16th May onwards from the information I have, KEEP IN MIND THIS COULD CHANGE.