There are a lot of checks and balances surrounding buybacks. Can't be over 5% of issued capital in any one year and has to be executed in a manner that doesn't influence the share price. As I understand it (and I am certainly not putting myself out as an expert on the subject), they cannot be a market maker, (set new share price high's).
I don't have any issues with it and in this case its clearly going to be eps accretive as the share price is still trading at a substantial discount to NTA and the forward PE is very cheap. This is ostensibly a property company trading at a very deep discount to a relatively easy measure of value to objectively quantify, (its net tangible asset backing that's valued every year by independent valuers).
Where buy-backs for some other companies get a bit murky is where the value of a company is not so easily and objectively quantifiable, i.e. where the majority of the value is made up of intangible assets.
Anyway...back to real estate...looks like the sleeping giant that is Auckland real estate is waking up which is great for MET as they have most of their villages there
https://www.landlords.co.nz/article/...+November+2019