Does the Army grant age waivers to officers looking to become rotary wing pilots (who are over the age of 32)?

The answer to your questions is "Yes, but it depends."

I was in Flight School (2010) with a guy that was a 37 year old prior enlisted soldier from the KYARNG. We (in the OHARNG) had a 1LT/CPT Branch transfer from the Cav at age 35 who went through IERW 2008ish. So waivers are out there. I haven't seen too many RA guys older than early 30's. But as far as the ARNG and USAR goes, there seems to be waves on their willingness to provide waivers. Typically your resume will have a big impact on whether or not they are interested in making the investment. States can be very stingy with them.

I, personally, am a huge fan of age waivers. Aviation is a much more "mature" environment and solid decision-making and leadership is required to be a safe and effective Aviator. Usually the two things keeping brand new pilots from advancing to Pilot in Command (PC) is "experience & maturity." Fort Rucker, however, shared a mini-survey that reported that older students did better academically at times, but struggled in the cockpit. (Old dog new tricks type of thing). I went through at 28-29... and I didn't have any problems. Our 37 year old did great too, but he had Master Aviation Wings from crewing Army FW Cargo aircraft for years. He wasn't a stranger to Aviation or the "nuances" of 'slipping the surly bonds of this Earth...

Not too much anymore

It all depends how badly the Army needs Pilots, everything ends up "the needs of the Army". It is worth checking with your local Warrant Officers to get their advice.