At today's Dragon Quest stream, other than revealing Dragon Quest Builders 2, Square Enix also announced that Dragon Quest, Dragon Quest II and Dragon Quest III will be released for PlayStation 4 and Nintendo 3DS in Japan.
Dragon Quest I and II will be released soon on August 10, with prices of 600 yen and 850 yen respectively excluding tax. Meanwhile, Dragon Quest III will be released later in late August at 1500 yen, excluding tax.
The first Dragon Quest is also available for free in Japan, but only for those who have played and beaten Dragon Quest XI by January 28, 2018. This Dragon Quest III release is also assumed to be the SNES port just like the other two games, so it will be a while until we can see the supposedly full-blown remake of DQIII on Unreal Engine 4.
Also, with this announcement, it marks that the Japanese 3DS now has every single numbered Dragon Quest titles to date available to play there, including the online Dragon Quest X.