Not the 5th GS, by any stretch of the imagination. But it's a matter of opinion.
It's special and unique. It's an individual event that greatly represents the success upon the medalists' country. Winning it is one of the hardest things to do in a Tennis players' career due to the 4 years it takes for the next one, no matter how hard trolls try to belittle it because their favourite flopped and a player they despise was victorious.
I personally preferred Murray winning Olympic Gold over Wimbledon last year. Djokovic and Federer will probably never win it for their country, while Andy still has several opportunities to win Wimbledon now that he has already given his country the greatest victory of all.
Yeah, you win an Olympic medal for your country unlike a slam title that you win mainly for yourself. But that doesn't mean OG are more important for players. And for the country, it's quite the same if a gold medal comes from singles or doubles, it's an Olympic gold anyway. That's why most singles players play also doubles at OG.
Anyway, I think they could just drop tennis from OG and introduce sports like beach volley for which OG is the biggest event and which attract spectators.