In order to get the RHCE, you need to have a valid (non-expired) RHCSA. After you pass EX294, if you renew your RHCSA, you'll automatically receive your RHCE -- with a validity dictated by the certificate that expires first (RHCSA or EX294).
Your RHCE will be automatically renwed/extended if you achieve any other certification contributing to RHCA path.
Hope this helps!
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