Records of astronomical observations of supernovae date millennia, with the most recent supernova in the Milky Way unquestionably observed by the naked eye being SN1604, in 1604 CE. Since the invention of the telescope, tens of thousands of supernovae have been observed, but they were all in other galaxies, leaving a disappointing gap of more than 400 years without observations in our own galaxy.
The closest and brightest observed supernova in recent times was SN1987A in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It was the first observed in every band of the electromagnetic spectrum and first detected via neutrinos. Its proximity allowed detailed observations and the test of models for supernovae formation.
Betelgeuse kindled speculations if it would go supernova when it started dimming in luminosity in later 2019. Later studies suggested that occluding dust may be the most likely culprit for the dimming and the star is unlikely to go supernova anytime soon. (see a Metaculus question about it)
The rate of supernovae per century in the Milky Way Galaxy is not well constrained, being frequently estimated between 1 and 10 SNe/century (see a list of estimates in Dragicevich et al., 1999 and Adams et al., 2013), but a recent estimate is of SNe/century by Adams et al. (2013). Most of these may be core-collapse supernovae, happening in the thin disk, and potentially obscured in the visible by gas and dust, but still observable in other parts of the spectrum, by gravitational waves or by neutrinos.
The observation of a supernova in the Milky Way Galaxy with the current multi-message astronomy technology could hugely improve our understanding of supernovae.
Will we observe a supernova in the Milky Way Galaxy before 2050?
This question will resolve as Yes if a supernova has been observed by humanity in the Milky Way Galaxy at any time between January 1, 2021 to January 1, 2050. This time period refers to the date when the supernova has been observed, not when the supernova itself occurs (which may be many hundreds of years in the past).