The word moe (which Metoro often used at moe glyphs) together with the visual impressions from the glyph type makes it easy to draw the conclusion that the intention could be to illustrate the end of a 'tired old' season.

However, another explanation is probably more correct - viz. that moe marks the time when next season is making itself noticed by light in the east (although the celestial body expected still has not risen). When the light announces the arrival of the moon it is called koata and this seems to have been a reason for great joy (koa).

...when the new moon appeared women assembled and bewailed those who had died since the last one, uttering the following lament: 'Alas! O moon! Thou has returned to life, but our departed beloved ones have not. Thou has bathed in the waiora a Tane, and had thy life renewed, but there is no fount to restore life to our departed ones. Alas'...

Possibly Metoro said gao takoa (koata reversed) for spring sun 'pushing the celestial roof higher'. The prominent necks of some moe glyphs could express how the 'sky roof' is being pushed up to let in light, e.g.:

 

	155 = 5 * 31		169 = 13 * 13	33
Ga6-6 (147)		Gb3-12 (303)			Ga2-3 (34)
sun pushing		moon pushing			?
360

The difference between an old season 'waning' and a new season 'pushing' is not very great.

A few notes on the structure of the Tahua text.