BOSTON/NEW YORK—Asset management firm Fidelity Investments on Monday said it had paused some voluntary return-to-office plans while Morgan Stanley’s CEO said he expects COVID-19 to be an issue through the next year, in a further sign that America’s financial industry is rethinking its return to “business as usual.” U.S. financial firms have been more proactive than other industries in encouraging employees to return to offices. Those plans have come under renewed scrutiny with COVID-19 cases again on the rise and as the Omicron variant of the coronavirus spreads swiftly. Some financial firms are now choosing to pull back on holiday parties, recommend booster shots, or even advise returning to work from home. “The private acknowledgement is that return to work plans set for January need another look,” said Neal Mills, chief medical officer for professional services firm Aon, who advises corporations on their return-to-work plans. Mills said he received calls …