Gibbs left for West Brom in a £7m deal towards the end of the transfer window, and Oxlade-Chamberlain followed him out the door as he made a deadline day move to Liverpool for £35m.
The English full-back came through the Arsenal youth system before breaking into the first team and going on to represent the Gunners 230 times in all competitions.
Although Oxlade-Chamberlain featured more than Gibbs for Arsenal last season, Wenger admitted that losing Gibbs hurt him more.
"Ideally you want stability and you want players who carry the values for the generations," Wenger said ahead of Gibbs' return to the Emirates with Tony Pulis' West Brom.
"Overall it's true that with Gibbs (it hurt) more than Chamberlain because he had been educated at Arsenal from the age of 10.
"When he arrived he was a left-winger. I transformed him into a full-back because he was not necessarily rated as a guy who would make it as a left winger but I saw something in him that was very intelligent, with pace, that made me feel he could make it as a left-back.
"(Academy players) carry the values that you think are important, which are based on mental qualities, humility, respect and commitment, and as well football qualities which means you always try to play in a positive way. Plus real team play and focusing on a collective way."
Gibbs made just 11 Premier League appearances last campaign and the summer arrival of Sead Kolasinac put him further down the pecking order and made a move away from Arsenal even more likely.
A move to Watford collapsed before West Brom stepped in on the final day of the transfer window, and Wenger was gutted to see Gibbs move on.
When asked if letting Gibbs leave felt like losing a family member, Wenger said: "Of course. And I believe that for (players that leave) it must be difficult to make that step as well.
"He did not ask to leave, it was a mutual decision. He wanted to play - he's 27, or 28. You want to play at that age.
"It was a difficult decision but on the other hand when a guy has given you so many years you have to accept that if he is not sure to play.
"It is a fact that we have got Kolasinac, you cannot keep three left-backs (along with Nacho Monreal)."