From an interview with IGN, Eiji Aonuma, producer of the Zelda franchise, stated that they may consider Linkle for future titles:
“I'm sure we will keep her in mind when thinking about future titles,”
“I had a chance to give feedback on Linkle during development, but the satisfying action of using a crossbow, which we developed for the spinoff title Link's Crossbow Training, was implemented this time completely by Koei Tecmo,” Aonuma said.
“It may feel a little different from other titles in the franchise, but she doesn’t feel out of place at all in the world of the Zelda games.”
Whether those titles are main ones or spin-offs was not mentioned.
Source: http://www.ign.com/articles/2015/12/08/nintendo-keeping-linkle-in-mind-for-future-zelda-games
Considering this was said by Aonuma, you can trust as much as Zelda for Wii U coming in 2015.
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