Model-based System Engineering (MBSE) of the Internet of Things (IoT) literature is broad, and analysis of this literature enables the identification of themes and potential future study topics that will influence system development. This paper reports on bibliometric literature analysis of MBSE of IoT. It considers conference and journal publication trends in the state-of-the-art to identify emerging research themes from the standpoint of trans/multi-disciplinary scholarship and technology. We used Elsevier's Scopus database to find relevant publications from January 2018 to December 2022. Using publication citation ranking and other factors (e.g., publication venues), we selected 110 articles and then analyzed them using BibExcel and VOSviewer software tools. With a modest decline in 2021, this analysis shows an overall increase in publications during the time period. A thematic analysis of the abstracts revealed a strong focus on the introduction of reference architectures and integration of MBSE with business and management methodologies like Agile and BPMN 2.0. Model-driven engineering and machine learning techniques are essential among the enablers for realization of complex heterogeneous IoT systems in the realm of Industry 4.0. We highlight these findings to better understand and meet the enduring challenge of scaling MBSE of IoT across diverse sectors like health, manufacturing, and transportation.INDEX TERMS BibExcel, bibliometrics, Internet of Things, industry 4.0, model-based system engineering, model-driven engineering, thematic analysis, VOSviewer.