I agree that inflation is a synthetic construct and doesn't necessarily need to exist. However, it persists because regardless of what name we assign the effect, it is a truism that market forces are never in perfect equillibrium so we'll always have some degree of inflation or deflation. Inflation is not an instantaneous metric, instead relying on prior and publically available CPI data (1) via the Bureau of Labor Stats site.
In general, as wages increase, the increase in buying power drives demand, driving increased product prices (2). Price increases are difficult to reverse. So, the OC is correct to question the impacts of UBI on inflation. I think it will increase inflation at inception, but the impact would probably quickly wane as UBI becomes standard (Caveat: I am strong against UBI for other reasons, I'm just making a point about inflation here)
Needless to say, plenty of discussion on this specific topic is found (3) by performing a search of the world wide web (www).
1. http://www.investopedia.com/terms/h/headline-inflation.asp
2. http://www.pewresearch.org/fact-tank/2014/10/09/for-most-wor...
3. http://basicincome.org/news/2016/11/will-basic-income-cause-...
Government deficits¹ generate inflation, what is a completely orthogonal concept to UBI.
1 - Among a few other factors, but the deficits are the one relevant here.