A villager will not lose its profession when the workstation is broken, or when is moved (via water) farther away from it. tried with multiple villagers, multiple types of professions and multiple different ranges.
In previous 1.14 versions villagers did lose their profession sometimes, but it very inconsistent. in 1.14.3 pre-release 1 they dont lose their profession at all
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As Mattes said, please make sure you are testing this between times 2000 and 9000. This timeframe also explains the "inconsistent" mechanics prior to 1.14.3 Pre-Release 1.
Villagers can only lose their workstation between a daytime of 2000 and 9000 when they are supposed to be working and therefor needing it. From my testing this still works fine.