Democratic Rep. David Wu of Oregon announced Tuesday that he will resign

[vectra]

Hello,

Here is a paragraph from an article "Congressman Resigns in Sex Scandal" published in NY Times:

Democratic Rep. David Wu of Oregon announced Tuesday that he will resign amid political fallout from an 18-year-old woman's allegations she had an unwanted sexual encounter with him.

The main verb "announced" is in the past tense, but it is followed by "will".
I have come across such things quite often lately.
The thing is I am more accustomed to using "would" after the main verb which is in the past tense.
Is it just common practice in newspapers and magazines to use this style or am I missing something?
If I am, what explanation should I give to my sharp-eyed students?

Thank you for your time and help.

[5jj]

Back-shifting (present to past, will to would) is almost always correct in reported speech introduced by a verb in a past tense. However, if the situation reported is still true at the time of reporting, then backshifting is not obligatory.