Technically there is no evidence supporting my claim, but look at the signals:

Off every one of her albums (exodus too, if you dont count "opening" as a real track) she always releases the first track as a single and promotes it the most (though Exodus is kinda the exception to all her tendencies). She also usually releases the title track too - she did for First Love, for Distance she released "Final Distance", and though Deep River wasn't a single, it had a PV and was somewhat promoted.

You should look at Hikki's wiki.theppn.org article, it is very informative and will make you a better fan overall.