...entered (into) a relationship with...

A Guardian article titled "Sergio Pérez ditches sponsor Hawkers after tweet on Trump’s Mexico wall plan" has this:

Pérez, a former team-mate of Jenson Button at McLaren, is now in his third year at Force India and has competed in more than 100 grands prix. The Mexican driver is financially backed by Carlos Slim, one of the world’s wealthiest men.

Pérez, who had just entered into a relationship with the sunglasses company, said: “I feel sorry because it is a great brand and they have done really well but I am not willing to stay there because basically the brand must be in charge of the social manager.

Another Guardian article titled "Scotland survey shows greater acceptance of same-sex relationships" has this:

The proportion of people expressing concerns about the impact of immigration on the Scottish labour market, by those from ethnic minorities and from eastern Europe, saw a significant decline between 2010 and 2015, but just under a third continued to agree or agree strongly that immigration “takes jobs away from people in Scotland”.

While only 5% of respondents in 2015 said they would be unhappy if a family member entered a relationship with a black or Asian person, opposition towards certain visible symbols of religion remained entrenched, with 65% agreeing that an employer should be able to insist that a Muslim woman remove her veil while at work, only reducing from 69% in 2010.

Is it not matter whether to keep the "into" or leave it out?
Or is there any contextual difference that justifies different structures?