Here´s an update direct from the French goevernment public information website https://www.service-public.fr/particuliers/vosdroits/F359 :
The online filing system will open “during April”, without being specific on the exact date.
The manual returns will be released at the end of April / beginning of May. This is particularly inconvenient for non-resident owners of French property declaring for the first time, for whom the filing deadline is 19th May ! It doesn´t give them much time at all. The good news is that, at least up until now, there have been no penalties payable for returns filed a little late.
Please visit our website for further information and assistance.