If entity A declares such and such incomes and expenses, it could be truthful or not.

If entity A is truthfully declaring such and such incomes and expenses, why would it reference it's own declaration as the "reported effective tax rate of 30%".

On the other hand if A is not truthfully declaring such and such incomes and expenses, and a legal team is very careful in maintaining an exact wording towards the government, then any tax-related comments by A which are not made by the legal team would either be self-censored or censored by the legal team to never reference "the effective tax rate" but rather a "reported" one, it basically reads like a superscript referring the reader to some other carefully worded fine print in other documents.

What prevented the more natural language of "[...] compared to the effective tax rate of 30%." ? Under what circumstances would you add such a word?

EDIT: this is not to say that this word constitutes an effective admission of lying, but rather that they don't actually want to talk about it, while pretending to be openly talking about it.

EDIT2: whenever companies get away with substantially lower tax rates, employee shortages in the rest of the economy can be seen as low-effective-taxed companies "stealing" employees from the rest of the economy, perhaps with or without approval from the government. If the government approves it is effectively a state-sponsored enterprise, and if it doesn't it would probably like to know about it since productivity of the economy could be improved by reassigning those employees into companies that allow themselves to be properly taxed (whatever that means!)