Overtalk: "So if your static lines ice up due to trapped water freezing as you climb, then those two differently derived static pressures will become increasingly unequal and the ASI will wind back to zero (in a climb/opposite in a descent). In the cruise, the IAS will simply "freeze"."
Why are you introducing static line freezing, when the only known suspect is the pitot tubes? Airspeed needs static pressure, as by definition it is static pressure subtracted from ram air pressure. Altitude, (static pressure) does not need Airspeed, except for trimming correction at high angles of attack. Altitude errors provide a whole different list of faults.
There is nothing in the ACARS reports suggesting Altitude Fault or disagree. Remember, the CMS report to Maintenance is a guide to the mechanic on which box to change on a short turnaround, so it may say ADR Fault, or ADR disagree. It doesn't say Airspeed Fault, or Altitude Fault. Those are left for the mechanic to find in the BITE, Built-In Test Equipment, testing.
Beyond that, a Pressure Altitude Fault will not trigger a TCAS Fault, as the Transponder is in between, relaying own ship altitude to the TCAS. Again, a Pressure Altitude Fault will cause the transponder to revert to Mode A, putting the TCAS in OFF mode. Remember the Legacy collision in Brazil? The transponder in Standby had put the TCAS in OFF, and didn't trigger a TCAS Fail, that the crew would have more likely seen.
GB