All perfect praise be to Allah
In fact this is proper way of talaq, the way of talaq which we use now a days, giving all 3 talaqs at once or with little breaks is not SUNNAH. And sunnah is against this practice. It is the need of hour to revive sunnah way of talaaq, which we were taught originally.
“Divorce according to Sunnah is that the woman is divorced in a state
of cleanliness (Tohr) without an intercourse, the husband gives one
divorces and leaves her as such till the iddat is over.”
(Mugni-ibneQuddamah Vol 7P. 98)
“The best procedure for divorce is that the husband should give one
divorce to his wife, and that too when she is in a state of
cleanliness and he had not had an intercourse with her. Then he should
lea ye her in the same state till the term of iddat is over. This
procedure is better, because the Companions of the Prophet (R) desired
that more than one divorce should not be given till the period of
iddat is over.” (Hidayah- Vol. 1 Page 179)
Rasulullah (SAW) was informed about a man who had divorced his wife
with all the three pronunciations, so
he(prophet S.A.W.W) stood up angrily and said: "Is the book of Allah played around with
while I am still in your midst?"...until a man got up (with his
unsheathed sword) and said: O Rasulullah, shall I not kill him?
(Although this hadees is about giving 3 talaaqs in one sitting, still it is relevant. And other two references are from two of the most acknowledged books of fiqh.)
One talaq is enough to break the legal binding of the husband and wife(after iddah period). And this is a preferable way, their are many hidden benefits if one follows this. One is that if someone divorces his wife in anger on some fake accusation, there's no way back after 3 talaqs, purpose of islam is not to separate people but to keep them unite. So, if one talaq is given, which is proper and valid way of talaq, than a person can make RUJU or re-marry if differences are resolved and accusations are proved wrong. This is one of the reasons why this is a prefered way. 3 talaqs are intended to be used for 3 separate nikahs, one talaq is enough to cancel one nika, second talq should be used on second nikah. Read more here.
About pressurizing for talaq
Having said that, i should also mention that IF your uncle gave this talaq on someone's pressure, than God forbid, the person who pressurized for this is in deep trouble. Talaaq is a huge thing, and is only ALLOWED to avoid more harm. If someone pressurized someone to give talaaq to his wife, he should repent to Allah.
“To Allah the most undesirable thing among the lawful things is
divorce.” (Abu Dawood)
And think about if someone is forcing this most undesirable thing when it could had been avoided without his/her pressure. May Allah forgive us all.
The Prophet (peace_be_upon_him) said: Anyone who
incites a woman against her husband or a slave against his master is
not one of us.
Also we all know about this hadees:
Jabir reported: The Messenger of Allah, peace and blessings be upon
him, said, “Verily, Satan places his throne over the water and he
sends out his troops. The closest to him in rank are the greatest at
causing tribulations. One of them says: I have done this and this.
Satan says: You have done nothing. Another one says: I did not leave
this man alone until I separated him from his wife. Satan embraces him
and he says: You have done well.”
Source: Ṣaḥīḥ Muslim 2813
The purpose of mentioning all above against divorce is to make it clear how bad it is considered to give divorce. A man has right to marry on his own, Allah has given this right to him, no one should take this right from him.
Allah knows best