Yes, it's real, gradual, and already priced into your bill. The FCC loosened carriers' obligation to maintain the legacy copper network, and major carriers have been filing to retire copper service area by area, including across Illinois. The playbook: stop investing in the copper plant, raise analog line prices sharply (many Illinois businesses have watched a POTS line go from $30-40 to $70-100+ per month), then formally retire the service where they can.
What this means practically if your business still has copper lines: the price will keep climbing, repairs will keep getting slower (fixing copper is now a scavenger hunt for parts and technicians), and eventually you'll get a retirement notice with a deadline. Moving on your own schedule beats moving on theirs.
Your voice lines are easy, hosted service replaces them outright, same numbers, lower cost. The lines that need actual planning are the ones people forget are copper: elevator phones, fire alarm panels, burglar alarm dialers, fax machines, gate boxes. Life-safety lines have code requirements (elevators and fire panels typically need supervised, battery-backed connections), which cellular-backed analog adapters are built to satisfy, but the swap should be coordinated with your alarm and elevator vendors, not improvised.
We do free copper audits for businesses in the 815: what's on each line, what it should move to, and what you're paying for lines that serve nothing, which we find on most audits.