From everything I have read, the claim that Diddy will serve only a little over 4 years is true. He was sentenced to 50 months in prison and fined $500,000, with his lawyers intending to appeal his conviction. Diddy was convicted of two counts of transportation for prostitution, while avoiding time for the biggest charges of racketeering and sex trafficking that were both dropped. Transportation for purposes of prostitution carries a maximum sentence of 10 years, with Diddy being convicted of 2 counts, there was a possibility of him serving 20 years. According to the BBC, prosecutors asked for a minimum of 11 years, but had to settle for 4 years and 2 months (50 months).
Sean "Diddy" Combs' lawyers stated that the prosecutors' attempt to sentence Diddy to a minimum of 11 years in prison would be a dramatic overreach and immediately asked for him to be released from federal detention until his sentencing hearing, suggesting a $1 million bail. However, a judge denied the request and said a significant sentence was required to send a message and act as a deterrent.
Sources:
https://www.bbc.com/news/articles/c0qz32wzeego
This article delves deeper into the other charges and lawsuits Diddy faced, explains what a racketeering charge is, and why it is significant that he wasn't convicted of it. It gives accounts of Cassie Ventura and his other exs' claims of abuse and their testimony while also highlighting the Mann Act, a US federal law that was passed specifically in order to combat human trafficking and sexual exploitation of women.
https://www.nbcnews.com/news/us-news/sean-diddy-combs-faces-strict-conditions-50-month-prison-sentence-rcna237818
This source gives more context on the case while also showing some of the court drawings and interviews NBC has done during the trial. It also details the extent of Diddy's probation which states that Combs’ probation officer can visit unannounced anytime, and he must live at an approved location. He must submit to searches of himself, property, residence, vehicle, papers, computers, and cellphones if there’s reasonable suspicion of a violation. He is not allowed to own, possess, or access firearms, ammunition, destructive devices, or any dangerous weapons. He must work at least 30 hours per week and is prohibited from communicating with anyone involved in criminal activities.
https://abcnews.go.com/US/sean-diddy-combs-appeal-conviction-prison-sentence/story?id=126698664
This article by ABC News talks about how In July, the jury acquitted Combs of the most serious charges he faced, including racketeering conspiracy and sex trafficking. It also gives an account of a letter Diddy wrote to the judgeafter his defence attorneys asked for a sentence of 14 months. Combs wrote in a letter to the judge overseeing his case before the sentencing."In my life, I have made many mistakes, but I am no longer running from them. I am so sorry for the hurt that I caused, but I understand that the mere words "I'm sorry" will never be good enough, as these words alone cannot erase the pain from the past."