What will happen to I-526 petitions recently filed through ELIS?

The recent change by USCIS (shutting down new ELIS filings as of June 15, 2015) will not affect your early filing. They will process your case, and you should not have to re-file by paper.

The change will not adversely affect customers who have pending or draft cases in the system as of June 15, 2015. USCIS will allow the standard 30 days for customers to complete and submit draft cases and will adjudicate all pending cases to completion. After June 15, 2015 anyone who needs to file a Form I-526 must file the paper version. Anyone who has already started an electronic Form I-526 on or before June 15 will have 30 days from the day they began their application to complete and submit it online. Customers who previously filed a Form I-526 electronically in ELIS will be able to access their account to check their case status, change their address, and respond to requests for evidence while USCIS processes their case. Customers who filed Form I-526 electronically will still be able to review and attest existing deal packages created by the document library manager.

I have never used the electronic filing. I believe they will continue processing filings that qualify before the stoppage.

USCIS stopped accepting ELIS I-526 filings on June 15. Given that you filed your application through ELIS in early May, your application should not be affected by this.

If you filed before the procedural change, then USCIS should accept the filing.

On June 15, 2015 they stopped accepting the electronically filed version of the form. If you filed before then, then it was accepted.