Here's the official publication:
It seems to be pretty inconclusive:
" Assuming the detected signals are real, we discuss their potential origin. Their source probably is the τ Bootis planetary system, and a possible explanation is radio emission from the exoplanet τ Bootis b via the cyclotron maser mechanism. Assuming a planetary origin, we derived limits for the planetary polar surface magnetic field strength, finding values compatible with theoretical predictions. Further observations with LOFAR-LBA and other low-frequency telescopes, such as NenuFAR or UTR-2, are required to confirm this possible first detection of an exoplanetary radio signal. "
" We cannot rule out stellar flares as the source of the emission and emission from the planet τ Boo remains a possible cause (see Section 6.1.4); follow-up observations are required (see next Section). For τ Boo, we also detect slowly variable emission in the range 21-30 MHz with a significance of 8.6σ (Table 4; Figure 5). A thorough analysis did not allow any firm conclusion: the existence of this signal can neither be confirmed with certainty, nor can it fully be refuted (Section 6.1.2)."
" For the υ And system, we found burst emission in the range 14-38 MHz with a marginal statistical significance of 2.2σ. We classify this as a non-detection. For τ Boo b and υ And b the phase coverage is 25% (Figure 2c) and 40% (Figure 2d), respectively. For this reason, we cannot rule out that we have missed radio emission concentrated at specific orbital phases not covered."
" Follow-up low-frequency radio observations (e.g., LOFAR, UTR-2, LWA-OLWA, NenuFAR) are needed to confirm our tentative detections from τ Boo and the marginal detection from υ And. Searching for periodicity in the detected signals will be crucial in confirming their origin and nature. Simultaneous observations between two facilities (e.g LOFAR and NenuFAR) is highly encouraged to rule out possible false-positives due to instrumental effects. We also hope to incorporate machine learning techniques (e.g., Baron 2019) into BOREALIS in the future to more efficiently search through the post-processing outputs.
It will be really cool if they can rule out false-positives and definitively confirm it in the future.
