Cat suddenly starts meowing regularly?

I realise this is a strange question but my theodore has suddenly found his voicebox! He has never meowed or purred since the day he was born. He shows his happiness in physical gestures and his moods. Some of you  Will know that he has had 3 major surgeries that were for urinary issues, and the other two were light sedations to try putting in a urinary stent. All these have occured since 1st of april this year.

Anyway, this week he has began to start meowing for us to take him out for walks or even just say hello. What on earth would cause him to suddenly start meowing to communicate when he never did this before? He still doesn't purr though. It's really cute and I haven't triggered sometimes that it's him meowing lol.

Some cats are just more vocal than others. My Lilith is very vocal. She will randomly start crying or meowing out of nowhere and I swear it sounds like she is calling to someone. At first I thought she was looking for my daughter after she went back to school but she came home for labor day and Lily did it then, too. Lily chirps, trills and sometimes I really think she can talk. I've heard noises from her that sounded just like a toddler saying helloooo? Mommy? and oh nooooo. Her sister Sophie is the opposite. She rarely makes noise except for when she is scolding me for not getting her dinner fast enough when I get home from work or when she's waking me up for breakfast at 5 AM.

Theodore would never meow, not even for food! He has NEVER meowed before this week, except for howling in extreme pain with his urinary blockages. It's just weird!
 

Mikki has done the same thing! She never used to make any noise...she's almost 10 and just started "talking" in the last 6 months!!

Wow! That is weird!

Maybe he never meowed before because he was in pain and now that he is feeling better he is gaining a new version of himself. Sometimes a change in behaviour goes with a change in health. Sounds like he has been recently seen by a vet so I would guess this is a positive change.