I was also surprised to see a photo on A.net of a 744 without the titles and the star......
It's the first time I see this with the new livery.
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Photo © Orrico emmanuel
With the old livery, the titles and the Israeli flag were removed when the planes were not flying El Al flights but were for instance operating for Arkia; since the introduction of the new livery, however, there were El Al planes seen flying even on Saturdays with the "whole" livery (although they were obviously not operating El Al flights...).
So I ignore the reason, but what you saw was for sure a 744 since no 742 has been painted in the new livery.