Royce doesn't have the pull Maluma has (and he's no Romeo Santos), bachata isn't as mainstream as reggaeton, there has been no promo for the single. I expect the song to grow more when the video is out, but they should hurry it up.
You're right. Deja Vu has 6 million views on Vevo already combining the audio and lyric video. Prince Royce's last single got 9.6 million views in 4 months combining the audio and official video!